Antibody drug conjugates (ADC) that bind to 191P4D12 proteins

ABSTRACT

Antibody drug conjugates (ADC&#39;s) that bind to 191P4D12 protein and variants thereof are described herein. 191P4D12 exhibits tissue specific expression in normal adult tissue, and is aberrantly expressed in the cancers listed in Table I. Consequently, the ADC&#39;s of the invention provide a therapeutic composition for the treatment of cancer.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.13/249,111, filed Sep. 29, 2011, which claims the benefit of priorityfrom U.S. Provisional Patent Application No. 61/387,933, filed Sep. 29,2010. The contents of each application listed in this paragraph arefully incorporated by reference herein.

SUBMISSION OF SEQUENCE LISTING ON ASCII TEXT FILE

The content of the following submission on ASCII text file isincorporated herein by reference in its entirety: a computer readableform (CRF) of the Sequence Listing (file name: 511582008203SeqList.txt,date recorded: Feb. 12, 2013, size: 41,958 bytes).

STATEMENT OF RIGHTS TO INVENTIONS MADE UNDER FEDERALLY SPONSOREDRESEARCH

Not applicable.

FIELD OF THE INVENTION

The invention described herein relates to antibodies, binding fragments,and antibody drug conjugates (ADCs) thereof, that bind proteins, termed191P4D12. The invention further relates to prognostic, prophylactic andtherapeutic methods and compositions useful in the treatment of cancersthat express 191P4D12.

BACKGROUND OF THE INVENTION

Cancer is the second leading cause of human death next to coronarydisease. Worldwide, millions of people die from cancer every year. Inthe United States alone, as reported by the American Cancer Society,cancer causes the death of well over a half-million people annually,with over 1.2 million new cases diagnosed per year. While deaths fromheart disease have been declining significantly, those resulting fromcancer generally are on the rise. In the early part of the next century,cancer is predicted to become the leading cause of death.

Worldwide, several cancers stand out as the leading killers. Inparticular, carcinomas of the lung, prostate, breast, colon, pancreas,ovary, and bladder represent the primary causes of cancer death. Theseand virtually all other carcinomas share a common lethal feature. Withvery few exceptions, metastatic disease from a carcinoma is fatal.Moreover, even for those cancer patients who initially survive theirprimary cancers, common experience has shown that their lives aredramatically altered. Many cancer patients experience strong anxietiesdriven by the awareness of the potential for recurrence or treatmentfailure. Many cancer patients experience physical debilitationsfollowing treatment. Furthermore, many cancer patients experience arecurrence.

Worldwide, prostate cancer is the fourth most prevalent cancer in men.In North America and Northern Europe, it is by far the most commoncancer in males and is the second leading cause of cancer death in men.In the United States alone, well over 30,000 men die annually of thisdisease—second only to lung cancer. Despite the magnitude of thesefigures, there is still no effective treatment for metastatic prostatecancer. Surgical prostatectomy, radiation therapy, hormone ablationtherapy, surgical castration and chemotherapy continue to be the maintreatment modalities. Unfortunately, these treatments are ineffectivefor many and are often associated with undesirable consequences.

On the diagnostic front, the lack of a prostate tumor marker that canaccurately detect early-stage, localized tumors remains a significantlimitation in the diagnosis and management of this disease. Although theserum prostate specific antigen (PSA) assay has been a very useful tool,its specificity and general utility is widely regarded as lacking inseveral important respects.

Progress in identifying additional specific markers for prostate cancerhas been improved by the generation of prostate cancer xenografts thatcan recapitulate different stages of the disease in mice. The LAPC (LosAngeles Prostate Cancer) xenografts are prostate cancer xenografts thathave survived passage in severe combined immune deficient (SCID) miceand have exhibited the capacity to mimic the transition from androgendependence to androgen independence (Klein et al., 1997, Nat. Med.3:402). More recently identified prostate cancer markers include PCTA-1(Su et al., 1996, Proc. Natl. Acad. Sci. USA 93: 7252),prostate-specific membrane antigen (PSMA) (Pinto et al., Clin Cancer Res1996 Sep. 2 (9): 1445-51), STEAP (Hubert, et al., Proc Natl Acad SciUSA. 1999 Dec. 7; 96(25): 14523-8) and prostate stem cell antigen (PSCA)(Reiter et al., 1998, Proc. Natl. Acad. Sci. USA 95: 1735).

While previously identified markers such as PSA have facilitated effortsto diagnose and treat prostate cancer, there is need for theidentification of additional markers and therapeutic targets forprostate and related cancers in order to further improve diagnosis andtherapy. An estimated 130,200 cases of colorectal cancer occurred in2000 in the United States, including 93,800 cases of colon cancer and36,400 of rectal cancer.

Colorectal cancers are the third most common cancers in men and women.Incidence rates declined significantly during 1992-1996 (−2.1% peryear). Research suggests that these declines have been due to increasedscreening and polyp removal, preventing progression of polyps toinvasive cancers. There were an estimated 56,300 deaths (47,700 fromcolon cancer, 8,600 from rectal cancer) in 2000, accounting for about11% of all U.S. cancer deaths.

At present, surgery is the most common form of therapy for colorectalcancer, and for cancers that have not spread, it is frequently curative.Chemotherapy, or chemotherapy plus radiation, is given before or aftersurgery to most patients whose cancer has deeply perforated the bowelwall or has spread to the lymph nodes. A permanent colostomy (creationof an abdominal opening for elimination of body wastes) is occasionallyneeded for colon cancer and is infrequently required for rectal cancer.There continues to be a need for effective diagnostic and treatmentmodalities for colorectal cancer.

Of all new cases of cancer in the United States, bladder cancerrepresents approximately 5 percent in men (fifth most common neoplasm)and 3 percent in women (eighth most common neoplasm). The incidence isincreasing slowly, concurrent with an increasing older population. In1998, there were an estimated 54,500 cases, including 39,500 in men and15,000 in women. The age-adjusted incidence in the United States is 32per 100,000 for men and eight per 100,000 in women. The historicmale/female ratio of 3:1 may be decreasing related to smoking patternsin women. There were an estimated 11,000 deaths from bladder cancer in1998 (7,800 in men and 3,900 in women). Bladder cancer incidence andmortality strongly increase with age and will be an increasing problemas the population becomes more elderly.

Most bladder cancers recur in the bladder. Bladder cancer is managedwith a combination of transurethral resection of the bladder (TUR) andintravesical chemotherapy or immunotherapy. The multifocal and recurrentnature of bladder cancer points out the limitations of TUR. Mostmuscle-invasive cancers are not cured by TUR alone. Radical cystectomyand urinary diversion is the most effective means to eliminate thecancer but carry an undeniable impact on urinary and sexual function.There continues to be a significant need for treatment modalities thatare beneficial for bladder cancer patients.

There were an estimated 164,100 new cases of lung and bronchial cancerin 2000, accounting for 14% of all U.S. cancer diagnoses. The incidencerate of lung and bronchial cancer is declining significantly in men,from a high of 86.5 per 100,000 in 1984 to 70.0 in 1996. In the 1990s,the rate of increase among women began to slow. In 1996, the incidencerate in women was 42.3 per 100,000.

Lung and bronchial cancer caused an estimated 156,900 deaths in 2000,accounting for 28% of all cancer deaths. During 1992-1996, mortalityfrom lung cancer declined significantly among men (−1.7% per year) whilerates for women were still significantly increasing (0.9% per year).Since 1987, more women have died each year of lung cancer than breastcancer, which, for over 40 years, was the major cause of cancer death inwomen. Decreasing lung cancer incidence and mortality rates most likelyresulted from decreased smoking rates over the previous 30 years;however, decreasing smoking patterns among women lag behind those ofmen. Of concern, although the declines in adult tobacco use have slowed,tobacco use in youth is increasing again.

Treatment options for lung and bronchial cancer are determined by thetype and stage of the cancer and include surgery, radiation therapy, andchemotherapy. For many localized cancers, surgery is usually thetreatment of choice. Because the disease has usually spread by the timeit is discovered, radiation therapy and chemotherapy are often needed incombination with surgery. Chemotherapy alone or combined with radiationis the treatment of choice for small cell lung cancer; on this regimen,a large percentage of patients experience remission, which in some casesis long lasting. There is however, an ongoing need for effectivetreatment and diagnostic approaches for lung and bronchial cancers.

An estimated 182,800 new invasive cases of breast cancer were expectedto occur among women in the United States during 2000. Additionally,about 1,400 new cases of breast cancer were expected to be diagnosed inmen in 2000. After increasing about 4% per year in the 1980s, breastcancer incidence rates in women have leveled off in the 1990s to about110.6 cases per 100,000.

In the U.S. alone, there were an estimated 41,200 deaths (40,800 women,400 men) in 2000 due to breast cancer. Breast cancer ranks second amongcancer deaths in women.

According to the most recent data, mortality rates declinedsignificantly during 1992-1996 with the largest decreases in youngerwomen, both white and black. These decreases were probably the result ofearlier detection and improved treatment.

Taking into account the medical circumstances and the patient'spreferences, treatment of breast cancer may involve lumpectomy (localremoval of the tumor) and removal of the lymph nodes under the arm;mastectomy (surgical removal of the breast) and removal of the lymphnodes under the arm; radiation therapy; chemotherapy; or hormonetherapy. Often, two or more methods are used in combination. Numerousstudies have shown that, for early stage disease, long-term survivalrates after lumpectomy plus radiotherapy are similar to survival ratesafter modified radical mastectomy. Significant advances inreconstruction techniques provide several options for breastreconstruction after mastectomy. Recently, such reconstruction has beendone at the same time as the mastectomy.

Local excision of ductal carcinoma in situ (DCIS) with adequate amountsof surrounding normal breast tissue may prevent the local recurrence ofthe DCIS. Radiation to the breast and/or tamoxifen may reduce the chanceof DCIS occurring in the remaining breast tissue. This is importantbecause DCIS, if left untreated, may develop into invasive breastcancer. Nevertheless, there are serious side effects or sequelae tothese treatments. There is, therefore, a need for efficacious breastcancer treatments.

There were an estimated 23,100 new cases of ovarian cancer in the UnitedStates in 2000. It accounts for 4% of all cancers among women and rankssecond among gynecologic cancers. During 1992-1996, ovarian cancerincidence rates were significantly declining. Consequent to ovariancancer, there were an estimated 14,000 deaths in 2000. Ovarian cancercauses more deaths than any other cancer of the female reproductivesystem.

Surgery, radiation therapy, and chemotherapy are treatment options forovarian cancer. Surgery usually includes the removal of one or bothovaries, the fallopian tubes (salpingo-oophorectomy), and the uterus(hysterectomy). In some very early tumors, only the involved ovary willbe removed, especially in young women who wish to have children. Inadvanced disease, an attempt is made to remove all intra-abdominaldisease to enhance the effect of chemotherapy. There continues to be animportant need for effective treatment options for ovarian cancer.

There were an estimated 28,300 new cases of pancreatic cancer in theUnited States in 2000. Over the past 20 years, rates of pancreaticcancer have declined in men. Rates among women have remainedapproximately constant but may be beginning to decline. Pancreaticcancer caused an estimated 28,200 deaths in 2000 in the United States.Over the past 20 years, there has been a slight but significant decreasein mortality rates among men (about −0.9% per year) while rates haveincreased slightly among women.

Surgery, radiation therapy, and chemotherapy are treatment options forpancreatic cancer. These treatment options can extend survival and/orrelieve symptoms in many patients but are not likely to produce a curefor most. There is a significant need for additional therapeutic anddiagnostic options for cancers. These include the use of antibodies,vaccines, and small molecules as treatment modalities. Additionally,there is also a need to use these modalities as research tools todiagnose, detect, monitor, and further the state of the art in all areasof cancer treatment and studies.

The therapeutic utility of monoclonal antibodies (mAbs) (G. Kohler andC. Milstein, Nature 256:495-497 (1975)) is being realized. Monoclonalantibodies have now been approved as therapies in transplantation,cancer, infectious disease, cardiovascular disease and inflammation.Different isotypes have different effector functions. Such differencesin function are reflected in distinct 3-dimensional structures for thevarious immunoglobulin isotypes (P. M. Alzari et al., Annual Rev.Immunol., 6:555-580 (1988)).

Because mice are convenient for immunization and recognize most humanantigens as foreign, mAbs against human targets with therapeuticpotential have typically been of murine origin. However, murine mAbshave inherent disadvantages as human therapeutics. They require morefrequent dosing as mAbs have a shorter circulating half-life in humansthan human antibodies. More critically, the repeated administration ofmurine antibodies to the human immune system causes the human immunesystem to respond by recognizing the mouse protein as a foreign andgenerating a human anti-mouse antibody (HAMA) response. Such a HAMAresponse may result in allergic reaction and the rapid clearing of themurine antibody from the system thereby rendering the treatment bymurine antibody useless. To avoid such affects, attempts to create humanimmune systems within mice have been attempted.

Initial attempts hoped to create transgenic mice capable of respondingto antigens with antibodies having human sequences (See Bruggemann etal., Proc. Nat'l. Acad. Sci. USA 86:6709-6713 (1989)), but were limitedby the amount of DNA that could be stably maintained by availablecloning vehicles. The use of yeast artificial chromosome (YAC) cloningvectors led the way to introducing large germline fragments of human Iglocus into transgenic mammals. Essentially a majority of the human V, D,and J region genes arranged with the same spacing found in the humangenome and the human constant regions were introduced into mice usingYACs. One such transgenic mouse strain is known as XenoMouse® mice andis commercially available from Amgen Fremont, Inc. (Fremont Calif.).

SUMMARY OF THE INVENTION

The invention provides antibodies, binding fragments, and antibody drugconjugates (ADCs) thereof that bind to 191P4D12 proteins and polypeptidefragments of 191P4D12 proteins. In some embodiments, the inventioncomprises fully human antibodies conjugated with a therapeutic agent. Incertain embodiments, there is a proviso that the entire nucleic acidsequence of FIG. 3 is not encoded and/or the entire amino acid sequenceof FIG. 2 is not prepared. In certain embodiments, the entire nucleicacid sequence of FIG. 3 is encoded and/or the entire amino acid sequenceof FIG. 2 is prepared, either of which are in respective human unit doseforms.

The invention further provides various immunogenic or therapeuticcompositions, such as antibody drug conjugates, and strategies fortreating cancers that express 191P4D12 such as cancers of tissues listedin Table I.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1. The cDNA and amino acid sequence of 191P4D12 is shown in FIG. 1.The start methionine is underlined. The open reading frame extends fromnucleic acid 264-1796 including the stop codon.

FIGS. 2A-B. Nucleic acid and amino acid sequences of 191P4D12antibodies. FIG. 2A. The cDNA and amino acid sequence of Ha22-2(2,4)6.1heavy chain. Double-underlined is the leader sequence, underlined is theheavy chain variable region, and underlined with a dashed line is thehuman IgG1 constant region. FIG. 2B. The cDNA and amino acid sequence ofHa22-2(2,4)6.1 light chain. Double-underlined is the leader sequence,underlined is the light chain variable region, and underlined with adashed line is the human kappa constant region.

FIGS. 3A-B. Amino acid sequences of 191P4D12 antibodies. FIG. 3A. Theamino acid sequence of Ha22-2(2,4)6.1 heavy chain. Double-underlined isthe leader sequence, underlined is the heavy chain variable region, andunderlined with a dashed line is the human IgG1 constant region. FIG.3B. The amino acid sequence of Ha22-2(2,4)6.1 light chain.Double-underlined is the leader sequence, underlined is the light chainvariable region, and underlined with a dashed line is the human kappaconstant region.

FIGS. 4A-B. Alignment of Ha22-2(2,4)6.1 antibodies to human Ig germlineFIG. 4A. Alignment of Ha22-2(2,4)6.1 heavy chain to human Ig germline.FIG. 4B. Alignment of Ha22-2(2,4)6.1 light chain to human Ig germline.

FIGS. 5A-B. Ha22-2(2,4)6.1 MAb binding assays. FIG. 5A: RAT-control andRAT-191P4D12 cells were stained with Ha22-2(2,4)6.1 MAb from eitherhybridoma or CHO cells. Binding was detected by flow cytometry. Resultsshow Ha22-2(2,4)6.1 MAb recombinantly expressed in CHO cells is secretedand binds specifically to cell-surface 191P4D12. FIG. 5B: Ha22-2(2,4)6.1MAb from either hybridoma or CHO cells was tested for binding torecombinant 191P4D12 purified extracellular protein by ELISA. Theresults show that 191P4D12 protein binding to Ha22-2(2,4)6.1 derivedfrom CHO and hybridoma was identical.

FIG. 6. Ha22-2(2,4)6.1vcMMAE Affinity Determination by FACS usingPC3-Human-191P4D12 cells. The affinity is 0.69 Kd.

FIG. 7. Ha22-2(2,4)6.1vcMMAE Affinity Determination by FACS usingPC3-Cynomolgus-191P4D12 cells. The affinity is 0.34 Kd.

FIG. 8. Ha22-2(2,4)6.1vcMMAE Affinity Determination by FACS usingPC3-Rat-191P4D12 cells. The affinity is 1.6 Kd.

FIGS. 9A-D. Cell cytotoxicity mediated by Ha22-2(2,4)6.1vcMMAE. FIG. 9A:Cell cytotoxicity assay using PC3-Human-191P4D12 cells. FIG. 9B: Cellcytotoxicity assay using PC3-Cynomolgus-191P4D12 cells. FIG. 9C: Cellcytotoxicity assay using PC3-Rat-191P4D12 cells. FIG. 9D: Cellcytotoxicity assay using PC3-Neo cells.

FIG. 10. Domain mapping of Ha22-(2,4)6.1 MAb by FACS.

FIG. 11. Ha22-2(2,4)6.1 MAb domain mapping by Western Blot Analysis.

FIG. 12. Evaluation of Ha22-2(2,4)6.1 MAb in the subcutaneous tumorformation model of human lung cancer xenograft AG-L4 in SCID mice. Theresults show that the 191P4D12 MAbs did not significantly inhibit tumorgrowth in human lung cancer xenograft AG-L4 in SCID mice.

FIG. 13. Evaluation of Ha22-2(2,4)6.1 MAb in the subcutaneous tumorformation model of human pancreatic cancer xenograft HPAC in SCID mice.The results show that the 191P4D12 MAbs did not inhibit tumor growth ina human pancreatic xenograft in SCID mice when compared to the controlantibody.

FIG. 14. Evaluation of Ha22-2(2,4)6.1 MAb in the subcutaneous tumorformation model of human pancreatic cancer xenograft AG-Panc3 in SCIDmice. The results show that the 191P4D12 MAbs did not inhibit tumorgrowth in a human pancreatic xenograft in SCID mice when compared to thecontrol antibody.

FIG. 15. Efficacy of Ha22-2(2,4)6.1-vcMMAE in subcutaneous establishedhuman lung cancer xenograft AG-L4 in SCID mice. The results show thattreatment with Ha22-2(2,4)6.1-vcMMAE significantly inhibited the growthof AG-L4 lung cancer xenografts implanted subcutaneously in nude micecompared to both the treated and untreated control.

FIG. 16. Efficacy of Ha22-2(2,4)6.1-vcMMAE in subcutaneous establishedhuman breast cancer xenograft BT-483 in SCID mice. The results show thattreatment with Ha22-2(2,4)6.1-vcMMAE significantly inhibited the growthof BT-483 breast tumor xenografts implanted subcutaneously in SCID micecompared to the treated and untreated control ADCs.

FIG. 17. Efficacy of Ha22-2(2,4)6.1-vcMMAE in subcutaneous establishedhuman bladder cancer xenograft AG-B1 in SCID mice. The results show thattreatment with Ha22-2(2,4)6.1-vcMMAE significantly inhibited the growthof AG-B1 bladder cancer xenografts as compared to the control ADCs.

FIG. 18. Efficacy of Ha22-2(2,4)6.1-vcMMAE in subcutaneous establishedhuman pancreatic cancer xenograft AG-Panc2 in SCID mice. The resultsshow that treatment with Ha22-2(2,4)6.1-vcMMAE significantly inhibitedthe growth of AG-Panc2 pancreatic cancer xenografts as compared to thecontrol ADCs.

FIG. 19. Efficacy of Ha22-2(2,4)6.1-vcMMAE in subcutaneous establishedhuman lung cancer xenograft AG-Panc4 in SCID mice. The results show thattreatment with Ha22-2(2,4)6.1-vcMMAE significantly inhibited the growthof AG-Panc4 pancreatic cancer xenografts as compared to the controlADCs.

FIG. 20. Efficacy of Ha22-2(2,4)6.1-vcMMAE at comparative dosage insubcutaneous established human bladder cancer xenograft AG-B8 in SCIDmice. The results show that treatment with Ha22-2(2,4)6.1vcMMAE at 10mg/kg significantly inhibited the growth of AG-B8 bladder cancerxenografts as compared to the Ha22-2(2,4)6.1vcMMAE at 5 mg/kg.

FIGS. 21A-N. Detection of 191P4D12 protein in cancer patient specimensby IHC. FIGS. 21A-B show bladder cancer specimens. FIGS. 21C-D showbreast cancer specimens. FIGS. 21E-F show pancreatic cancer specimens.FIGS. 21G-H show lung cancer specimens. FIGS. 2114 show ovarian cancerspecimens. FIGS. 21K-L show esophageal cancer specimens. FIG. 21M-N showesophageal cancer specimens.

FIGS. 22A-B. Show binding curves used to determine the affinity ofHa22-2(2,4)6.1 Mab and Ha22-2(2,4)6.1vcMMAE to purified recombinant191P4D12 (ECD amino acids 1-348).

FIGS. 23A-D. Show binding of Ha22-2(2,4)6.1 to PC3 cells expressing191P4D12 (FIG. 23A) and orthologs from cynomolgus monkey (FIG. 23B), rat(FIG. 23C) and mouse (FIG. 23D).

FIGS. 24A-D. Show binding of Ha22-2(2,4)6.1 to the double mutant A76I,S91N is similar to murine ortholog binding.

FIG. 25. Shows a model of the V-domain of 191P4D12 based on publishedcrystal structure data for family members of 191P4D12 and Ig-domaincontaining proteins using PyMOL. The positions of Ala-76 (stippled) andSer-91 (crosshatched) are shown.

FIGS. 26A-C. Shows binding of Ha22-2(2,4)6.1 binds to V-domainexpressing cells (FIG. 26A) as well as wild-type 191P4D12 (FIG. 26B),but not to C1C2 domain expressing cells generated earlier (FIG. 26C).

DETAILED DESCRIPTION OF THE INVENTION

Outline of Sections

-   I.) Definitions-   II.) 191P4D12 Antibodies-   III.) Antibody Drug Conjugates Generally    -   III(A). Maytansinoids    -   III(B). Auristatins and dolostatins    -   III(C). Calicheamicin    -   III(D). Other Cytotoxic Agents-   IV.) Antibody Drug Conjugates which Bind 191P4D12-   V.) Linker Units-   VI.) The Stretcher Unit-   VII.) The Amino Acid Unit-   VIII.) The Spacer Unit-   IX.) The Drug Unit-   X.) Drug Loading-   XI.) Methods of Determining Cytotoxic effect of ADCs-   XII.) Treatment of Cancer(s) Expressing 191P4D12-   XIII.) 191P4D12 as a Target for Antibody-based Therapy-   XIV.) 191P4D12 ADC Cocktails-   XV.) Combination Therapy-   XVI.) Kits/Articles of Manufacture    I.) Definitions:

Unless otherwise defined, all terms of art, notations and otherscientific terms or terminology used herein are intended to have themeanings commonly understood by those of skill in the art to which thisinvention pertains. In some cases, terms with commonly understoodmeanings are defined herein for clarity and/or for ready reference, andthe inclusion of such definitions herein should not necessarily beconstrued to represent a substantial difference over what is generallyunderstood in the art. Many of the techniques and procedures describedor referenced herein are well understood and commonly employed usingconventional methodology by those skilled in the art, such as, forexample, the widely utilized molecular cloning methodologies describedin Sambrook et al., Molecular Cloning: A Laboratory Manual 2nd. edition(1989) Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y. Asappropriate, procedures involving the use of commercially available kitsand reagents are generally carried out in accordance with manufacturerdefined protocols and/or parameters unless otherwise noted.

When a trade name is used herein, reference to the trade name alsorefers to the product formulation, the generic drug, and the activepharmaceutical ingredient(s) of the trade name product, unless otherwiseindicated by context.

The terms “advanced cancer”, “locally advanced cancer”, “advanceddisease” and “locally advanced disease” mean cancers that have extendedthrough the relevant tissue capsule, and are meant to include stage Cdisease under the American Urological Association (AUA) system, stageC1-C2 disease under the Whitmore-Jewett system, and stage T3-T4 and N+disease under the TNM (tumor, node, metastasis) system. In general,surgery is not recommended for patients with locally advanced disease,and these patients have substantially less favorable outcomes comparedto patients having clinically localized (organ-confined) cancer.

The abbreviation “AFP” refers todimethylvaline-valine-dolaisoleuine-dolaproine-phenylalanine-p-phenylenediamine(see Formula XVI infra).

The abbreviation “MMAE” refers to monomethyl auristatin E (see FormulaXI infra).

The abbreviation “AEB” refers to an ester produced by reactingauristatin E with paraacetyl benzoic acid (see Formula XX infra).

The abbreviation “AEVB” refers to an ester produced by reactingauristatin E with benzoylvaleric acid (see Formula XXI infra).

The abbreviation “MMAF” refers todovaline-valine-dolaisoleuine-dolaproine-phenylalanine (see Formula XVIVinfra).

Unless otherwise noted, the term “alkyl” refers to a saturated straightor branched hydrocarbon having from about 1 to about 20 carbon atoms(and all combinations and subcombinations of ranges and specific numbersof carbon atoms therein), with from about 1 to about 8 carbon atomsbeing preferred. Examples of alkyl groups are methyl, ethyl, n-propyl,iso-propyl, n-butyl, iso-butyl, sec-butyl, tert-butyl, n-pentyl,2-pentyl, 3-pentyl, 2-methyl-2-butyl, n-hexyl, n-heptyl, n-octyl,n-nonyl, n-decyl, 3-methyl-2-butyl, 3-methyl-1-butyl, 2-methyl-1-butyl,1-hexyl, 2-hexyl, 3-hexyl, 2-methyl-2-pentyl, 3-methyl-2-pentyl,4-methyl-2-pentyl, 3-methyl-3-pentyl, 2-methyl-3-pentyl,2,3-dimethyl-2-butyl, and 3,3-dimethyl-2-butyl.

Alkyl groups, whether alone or as part of another group, can beoptionally substituted with one or more groups, preferably 1 to 3 groups(and any additional substituents selected from halogen), including, butnot limited to, -halogen, —O—(C₁-C₈ alkyl), —O—(C₂-C₈ alkenyl),—O—(C₂-C₈ alkynyl), -aryl, —C(O)R′, —OC(O)R′, —C(O)OR′, —C(O)NH₂,—C(O)NHR′, —C(O)N(R′)₂, —NHC(O)R′, —SR′, —SO₃R′, —S(O)₂R′, —S(O)R′, —OH,═O, —N₃, —NH₂, —NH(R′), —N(R′)₂ and —CN, where each R′ is independentlyselected from —H, —C₁-C₈ alkyl, —C₂-C₈ alkenyl, —C₂-C₈ alkynyl, or-aryl, and wherein said —O—(C₁-C₈ alkyl), —O—(C₂-C₈ alkenyl), —O—(C₂-C₈alkynyl), -aryl, —C₁-C₈ alkyl, —C₂-C₈ alkenyl, and —C₂-C₈ alkynyl groupscan be optionally further substituted with one or more groups including,but not limited to, —C₁-C₈ alkyl, —C₂-C₈ alkenyl, —C₂-C₈ alkynyl,-halogen, —O—(C₁-C₈ alkyl), —O—(C₂-C₈ alkenyl), —O—(C₂-C₈ alkynyl),-aryl, —C(O)R″, —OC(O)R″, —C(O)OR″, —C(O)NH₂, —C(O)NHR″, —C(O)N(R″)₂,—NHC(O)R″, —SR″, —SO₃R″, —S(O)₂R″, —S(O)R″, —OH, —N₃, —NH₂, —NH(R″),—N(R″)₂ and —CN, where each R″ is independently selected from —H, —C₁-C₈alkyl, —C₂-C₈ alkenyl, —C₂-C₈ alkynyl, or -aryl.

Unless otherwise noted, the terms “alkenyl” and “alkynyl” refer tostraight and branched carbon chains having from about 2 to about 20carbon atoms (and all combinations and subcombinations of ranges andspecific numbers of carbon atoms therein), with from about 2 to about 8carbon atoms being preferred. An alkenyl chain has at least one doublebond in the chain and an alkynyl chain has at least one triple bond inthe chain. Examples of alkenyl groups include, but are not limited to,ethylene or vinyl, allyl, -1-butenyl, -2-butenyl, -isobutylenyl,-1-pentenyl, -2-pentenyl, -3-methyl-1-butenyl, -2-methyl-2-butenyl, and-2,3-dimethyl-2-butenyl. Examples of alkynyl groups include, but are notlimited to, acetylenic, propargyl, acetylenyl, propynyl, -1-butynyl,-2-butynyl, -1-pentynyl, -2-pentynyl, and -3-methyl-1 butynyl.

Alkenyl and alkynyl groups, whether alone or as part of another group,can be optionally substituted with one or more groups, preferably 1 to 3groups (and any additional substituents selected from halogen),including but not limited to, -halogen, —O—(C₁-C₈ alkyl), —O—(C₂-C₈alkenyl), —O—(C₂-C₈ alkynyl), -aryl, —C(O)R′, —OC(O)R′, —C(O)OR′,—C(O)NH₂, —C(O)NHR′, —C(O)N(R′)₂, —NHC(O)R′, —SR′, —SO₃R′, —S(O)₂R′,—S(O)R′, —OH, ═O, —N₃, —NH₂, —NH(R′), —N(R′)₂ and —CN, where each R′ isindependently selected from —H, —C₁-C₈ alkyl, —C₂-C₈ alkyenl, —C₂-C₈alkynyl, or -aryl and wherein said —O—(C₁-C₈ alkyl), —O—(C₂-C₈ alkenyl),—O—(C₂-C₈ alkynyl), -aryl, —C₁-C₈ alkyl, —C₂-C₈ alkenyl, and —C₂-C₈alkynyl groups can be optionally further substituted with one or moresubstituents including, but not limited to, —C₁-C₈ alkyl, —C₂-C₈alkenyl, —C₂-C₈ alkynyl, -halogen, —O—(C₁-C₈ alkyl), —O—(C₂-C₈ alkenyl),—O—(C₂C₈ alkynyl), -aryl, —C(O)R″, —OC(O)R″, —C(O)OR″, —C(O)NH₂,—C(O)NHR″, —C(O)N(R″)₂, —NHC(O)R″, —SR″, —SO₃R″, —S(O)₂R″, —S(O)R″, —OH,—N₃, —NH₂, —NH(R″), —N(R″)₂ and —CN, where each R″ is independentlyselected from —H, —C₁-C₈ alkyl, —C₂-C₈ alkenyl, —C₂-C₈ alkynyl, or-aryl.

Unless otherwise noted, the term “alkylene” refers to a saturatedbranched or straight chain hydrocarbon radical having from about 1 toabout 20 carbon atoms (and all combinations and subcombinations ofranges and specific numbers of carbon atoms therein), with from about 1to about 8 carbon atoms being preferred and having two monovalentradical centers derived by the removal of two hydrogen atoms from thesame or two different carbon atoms of a parent alkane. Typical alkylenesinclude, but are not limited to, methylene, ethylene, propylene,butylene, pentylene, hexylene, heptylene, ocytylene, nonylene, decalene,1,4-cyclohexylene, and the like. Alkylene groups, whether alone or aspart of another group, can be optionally substituted with one or moregroups, preferably 1 to 3 groups (and any additional substituentsselected from halogen), including, but not limited to, -halogen,—O—(C₁-C₈ alkyl), —O—(C₂-C₈ alkenyl), —O—(C₂-C₈ alkynyl), -aryl,—C(O)R′, —OC(O)R′, —C(O)OR′, —C(O)NH₂, —C(O)NHR′, —C(O)N(R′)₂,—NHC(O)R′, —SR′, —SO₃R′, —S(O)₂R′, —S(O)R′, —OH, ═O, —N₃, —NH₂, —NH(R′),—N(R′)₂ and —CN, where each R′ is independently selected from —H, —C₁-C₈alkyl, —C₂-C₈ alkenyl, —C₂-C₈ alkynyl, or -aryl and wherein said—O—(C₁-C₈ alkyl), —O—(C₂-C₈ alkenyl), —O—(C₂-C₈ alkynyl), -aryl, —C₁-C₈alkyl, —C₂-C₈ alkenyl, and —C₂-C₈ alkynyl groups can be furtheroptionally substituted with one or more substituents including, but notlimited to, —C₁-C₈ alkyl, —C₂-C₈ alkenyl, —C₂-C₈ alkynyl, -halogen,—O—(C₁-C₈ alkyl), —O—(C₂-C₈ alkenyl), —O—(C₂-C₈ alkynyl), -aryl,—C(O)R″, —OC(O)R″, —C(O)OR″, —C(O)NH₂, —C(O)NHR″, —C(O)N(R″)₂,—NHC(O)R″, —SR″, —SO₃R″, —S(O)₂R″, —S(O)R″, —OH, —N₃, —NH₂, —NH(R″),—N(R″)₂ and —CN, where each R″ is independently selected from —H, —C₁-C₈alkyl, —C₂-C₈ alkenyl, —C₂-C₈ alkynyl, or -aryl.

Unless otherwise noted, the term “alkenylene” refers to an optionallysubstituted alkylene group containing at least one carbon-carbon doublebond. Exemplary alkenylene groups include, for example, ethenylene(—CH═CH—) and propenylene (—CH═CHCH₂—).

Unless otherwise noted, the term “alkynylene” refers to an optionallysubstituted alkylene group containing at least one carbon-carbon triplebond. Exemplary alkynylene groups include, for example, acetylene(—C≡C—), propargyl (—CH₂C≡C—), and 4-pentynyl (—CH₂CH₂CH₂C≡CH—).

Unless otherwise noted, the term “aryl” refers to a monovalent aromatichydrocarbon radical of 6-20 carbon atoms (and all combinations andsubcombinations of ranges and specific numbers of carbon atoms therein)derived by the removal of one hydrogen atom from a single carbon atom ofa parent aromatic ring system. Some aryl groups are represented in theexemplary structures as “Ar”. Typical aryl groups include, but are notlimited to, radicals derived from benzene, substituted benzene, phenyl,naphthalene, anthracene, biphenyl, and the like.

An aryl group, whether alone or as part of another group, can beoptionally substituted with one or more, preferably 1 to 5, or even 1 to2 groups including, but not limited to, -halogen, —C₁-C₈ alkyl, —C₂-C₈alkenyl, —C₂-C₈ alkynyl, —O—(C₁-C₈ alkyl), —O—(C₂-C₈ alkenyl), —O—(C₂-C₈alkynyl), -aryl, —C(O)R′, —OC(O)R′, —C(O)OR′, —C(O)NH₂, —C(O)NHR′,—C(O)N(R′)₂, —NHC(O)R′, —SR′, —SO₃R′, —S(O)₂R′, —S(O)R′, —OH, —NO₂, —N₃,—NH₂, —NH(R′), —N(R′)₂ and —CN, where each R′ is independently selectedfrom —H, —C₁-C₈ alkyl, —C₂-C₈ alkenyl, —C₂-C₈ alkynyl, or -aryl andwherein said —C₁-C₈ alkyl, —C₂-C₈ alkenyl, —C₂-C₈ alkynyl, O—(C₁-C₈alkyl), —O—(C₂-C₈ alkenyl), —O—(C₂-C₈ alkynyl), and -aryl groups can befurther optionally substituted with one or more substituents including,but not limited to, —C₁-C₈ alkyl, —C₂-C₈ alkenyl, —C₂-C₈ alkynyl,-halogen, —O—(C₁-C₈ alkyl), —O—(C₂-C₈ alkenyl), —O—(C₂-C₈ alkynyl),-aryl, —C(O)R″, —OC(O)R″, —C(O)OR″, —C(O)NH₂, —C(O)NHR″, —C(O)N(R″)₂,—NHC(O)R″, —SR″, —SO₃R″, —S(O)₂R″, —S(O)R″, —OH, —N₃, —NH₂, —NH(R″),—N(R″)₂ and —CN, where each R″ is independently selected from —H, —C₁-C₈alkyl, —C₂-C₈ alkenyl, —C₂-C₈ alkynyl, or -aryl.

Unless otherwise noted, the term “arylene” refers to an optionallysubstituted aryl group which is divalent (i.e., derived by the removalof two hydrogen atoms from the same or two different carbon atoms of aparent aromatic ring system) and can be in the ortho, meta, or paraconfigurations as shown in the following structures with phenyl as theexemplary aryl group.

Typical “—(C₁-C₈ alkylene)aryl,” “—(C₂-C₈ alkenylene)aryl”, “and —(C₂-C₈alkynylene)aryl” groups include, but are not limited to, benzyl,2-phenylethan-1-yl, 2-phenylethen-1-yl, naphthylmethyl,2-naphthylethan-1-yl, 2-naphthylethen-1-yl, naphthobenzyl,2-naphthophenylethan-1-yl and the like.

Unless otherwise noted, the term “heterocycle,” refers to a monocyclic,bicyclic, or polycyclic ring system having from 3 to 14 ring atoms (alsoreferred to as ring members) wherein at least one ring atom in at leastone ring is a heteroatom selected from N, O, P, or S (and allcombinations and subcombinations of ranges and specific numbers ofcarbon atoms and heteroatoms therein). The heterocycle can have from 1to 4 ring heteroatoms independently selected from N, O, P, or S. One ormore N, C, or S atoms in a heterocycle can be oxidized. A monocylicheterocycle preferably has 3 to 7 ring members (e.g., 2 to 6 carbonatoms and 1 to 3 heteroatoms independently selected from N, O, P, or S),and a bicyclic heterocycle preferably has 5 to 10 ring members (e.g., 4to 9 carbon atoms and 1 to 3 heteroatoms independently selected from N,O, P, or S). The ring that includes the heteroatom can be aromatic ornon-aromatic. Unless otherwise noted, the heterocycle is attached to itspendant group at any heteroatom or carbon atom that results in a stablestructure.

Heterocycles are described in Paquette, “Principles of ModernHeterocyclic Chemistry” (W. A. Benjamin, New York, 1968), particularlyChapters 1, 3, 4, 6, 7, and 9; “The Chemistry of Heterocyclic Compounds,A series of Monographs” (John Wiley & Sons, New York, 1950 to present),in particular Volumes 13, 14, 16, 19, and 28; and J. Am. Chem. Soc.82:5566 (1960).

Examples of “heterocycle” groups include by way of example and notlimitation pyridyl, dihydropyridyl, tetrahydropyridyl (piperidyl),thiazolyl, pyrimidinyl, furanyl, thienyl, pyrrolyl, pyrazolyl,imidazolyl, tetrazolyl, benzofuranyl, thianaphthalenyl, indolyl,indolenyl, quinolinyl, isoquinolinyl, benzimidazolyl, piperidinyl,4-piperidonyl, pyrrolidinyl, 2-pyrrolidonyl, pyrrolinyl,tetrahydrofuranyl, bis-tetrahydrofuranyl, tetrahydropyranyl,bis-tetrahydropyranyl, tetrahydroquinolinyl, tetrahydroisoquinolinyl,decahydroquinolinyl, octahydroisoquinolinyl, azocinyl, triazinyl,6H-1,2,5-thiadiazinyl, 2H,6H-1,5,2-dithiazinyl, thienyl, thianthrenyl,pyranyl, isobenzofuranyl, chromenyl, xanthenyl, phenoxathinyl,2H-pyrrolyl, isothiazolyl, isoxazolyl, pyrazinyl, pyridazinyl,indolizinyl, isoindolyl, 3H-indolyl, 1H-indazolyl, purinyl,4H-quinolizinyl, phthalazinyl, naphthyridinyl, quinoxalinyl,quinazolinyl, cinnolinyl, pteridinyl, 4H-carbazolyl, carbazolyl,β-carbolinyl, phenanthridinyl, acridinyl, pyrimidinyl, phenanthrolinyl,phenazinyl, phenothiazinyl, furazanyl, phenoxazinyl, isochromanyl,chromanyl, imidazolidinyl, imidazolinyl, pyrazolidinyl, pyrazolinyl,piperazinyl, indolinyl, isoindolinyl, quinuclidinyl, morpholinyl,oxazolidinyl, benzotriazolyl, benzisoxazolyl, oxindolyl, benzoxazolinyl,and isatinoyl. Preferred “heterocycle” groups include, but are notlimited to, benzofuranyl, benzothiophenyl, indolyl, benzopyrazolyl,coumarinyl, isoquinolinyl, pyrrolyl, thiophenyl, furanyl, thiazolyl,imidazolyl, pyrazolyl, triazolyl, quinolinyl, pyrimidinyl, pyridinyl,pyridonyl, pyrazinyl, pyridazinyl, isothiazolyl, isoxazolyl andtetrazolyl.

A heterocycle group, whether alone or as part of another group, can beoptionally substituted with one or more groups, preferably 1 to 2groups, including but not limited to, —C₁-C₈ alkyl, —C₂-C₈ alkenyl,—C₂-C₈ alkynyl, -halogen, —O—(C₁-C₈ alkyl), —O—(C₂-C₈ alkenyl),—O—(C₂-C₈ alkynyl), -aryl, —C(O)R′, —OC(O)R′, —C(O)OR′, —C(O)NH₂,—C(O)NHR′, —C(O)N(R′)₂, —NHC(O)R′, —SR′, —SO₃R′, —S(O)₂R′, —S(O)R′, —OH,—N₃, —NH₂, —NH(R′), —N(R′)₂ and —CN, where each R′ is independentlyselected from —H, —C₁-C₈ alkyl, —C₂-C₈ alkenyl, —C₂-C₈ alkynyl, or -aryland wherein said —O—(C₁-C₈ alkyl), —O—(C₂-C₈ alkenyl), —O—(C₂-C₈alkynyl), —C₁-C₈ alkyl, —C₂-C₈ alkenyl, —C₂-C₈ alkynyl, and -aryl groupscan be further optionally substituted with one or more substituentsincluding, but not limited to, —C₁-C₈ alkyl, —C₂-C₈ alkenyl, —C₂-C₈alkynyl, -halogen, —O—(C₁-C₈ alkyl), —O—(C₂-C₈ alkenyl), —O—(C₂-C₈alkynyl), -aryl, —C(O)R″, —OC(O)R″, —C(O)OR″, —C(O)NH₂, —C(O)NHR″,—C(O)N(R″)₂, —NHC(O)R″, —SR″, —SO₃R″, —S(O)₂R″, —S(O)R″, —OH, —N₃, —NH₂,—NH(R″), —N(R″)₂ and —CN, where each R″ is independently selected from—H, —C₁-C₈ alkyl, —C₂-C₈ alkenyl, —C₂-C₈ alkynyl, or aryl.

By way of example and not limitation, carbon-bonded heterocycles can bebonded at the following positions: position 2, 3, 4, 5, or 6 of apyridine; position 3, 4, 5, or 6 of a pyridazine; position 2, 4, 5, or 6of a pyrimidine; position 2, 3, 5, or 6 of a pyrazine; position 2, 3, 4,or 5 of a furan, tetrahydrofuran, thiofuran, thiophene, pyrrole ortetrahydropyrrole; position 2, 4, or 5 of an oxazole, imidazole orthiazole; position 3, 4, or 5 of an isoxazole, pyrazole, or isothiazole;position 2 or 3 of an aziridine; position 2, 3, or 4 of an azetidine;position 2, 3, 4, 5, 6, 7, or 8 of a quinoline; or position 1, 3, 4, 5,6, 7, or 8 of an isoquinoline. Still more typically, carbon bondedheterocycles include 2-pyridyl, 3-pyridyl, 4-pyridyl, 5-pyridyl,6-pyridyl, 3-pyridazinyl, 4-pyridazinyl, 5-pyridazinyl, 6-pyridazinyl,2-pyrimidinyl, 4-pyrimidinyl, 5-pyrimidinyl, 6-pyrimidinyl, 2-pyrazinyl,3-pyrazinyl, 5-pyrazinyl, 6-pyrazinyl, 2-thiazolyl, 4-thiazolyl, or5-thiazolyl.

By way of example and not limitation, nitrogen bonded heterocycles canbe bonded at position 1 of an aziridine, azetidine, pyrrole,pyrrolidine, 2-pyrroline, 3-pyrroline, imidazole, imidazolidine,2-imidazoline, 3-imidazoline, pyrazole, pyrazoline, 2-pyrazoline,3-pyrazoline, piperidine, piperazine, indole, indoline, or 1H-indazole;position 2 of a isoindole, or isoindoline; position 4 of a morpholine;and position 9 of a carbazole, or β-carboline. Still more typically,nitrogen bonded heterocycles include 1-aziridyl, 1-azetedyl, 1-pyrrolyl,1-imidazolyl, 1-pyrazolyl, and 1-piperidinyl.

Unless otherwise noted, the term “carbocycle,” refers to a saturated orunsaturated non-aromatic monocyclic, bicyclic, or polycyclic ring systemhaving from 3 to 14 ring atoms (and all combinations and subcombinationsof ranges and specific numbers of carbon atoms therein) wherein all ofthe ring atoms are carbon atoms. Monocyclic carbocycles preferably have3 to 6 ring atoms, still more preferably 5 or 6 ring atoms. Bicycliccarbocycles preferably have 7 to 12 ring atoms, e.g., arranged as abicyclo [4,5], [5,5], [5,6] or [6,6] system, or 9 or 10 ring atomsarranged as a bicyclo [5,6] or [6,6] system. The term “carbocycle”includes, for example, a monocyclic carbocycle ring fused to an arylring (e.g., a monocyclic carbocycle ring fused to a benzene ring).Carbocyles preferably have 3 to 8 carbon ring atoms.

Carbocycle groups, whether alone or as part of another group, can beoptionally substituted with, for example, one or more groups, preferably1 or 2 groups (and any additional substituents selected from halogen),including, but not limited to, -halogen, —C₁-C₈ alkyl, —C₂-C₈ alkenyl,—C₂-C₈ alkynyl, —O—(C₁-C₈ alkyl), —O—(C₂-C₈ alkenyl), —O—(C₂-C₈alkynyl), -aryl, —C(O)R′, —OC(O)R′, −C(O)OR′, —C(O)NH₂, —C(O)NHR′,—C(O)N(R′)₂, —NHC(O)R′, —SR′, —SO₃R′, —S(O)₂R′, —S(O)R′, —OH, ═O, —N₃,—NH₂, —NH(R′), —N(R′)₂ and —CN, where each R′ is independently selectedfrom —H, —C₁-C₈ alkyl, —C₂-C₈ alkenyl, —C₂-C₈ alkynyl, or -aryl andwherein said —C₁-C₈ alkyl, —C₂-C₈ alkenyl, —C₂-C₈ alkynyl, —O—(C₁-C₈alkyl), —O—(C₂-C₈ alkenyl), —O—(C₂-C₈ alkynyl), and -aryl groups can befurther optionally substituted with one or more substituents including,but not limited to, —C₁-C₈ alkyl, —C₂-C₈ alkenyl, —C₂-C₈ alkynyl,—halogen, —O—(C₁-C₈ alkyl), —O—(C₂-C₈ alkenyl), —O—(C₂-C₈ alkynyl),-aryl, —C(O)R″, —OC(O)R″, —C(O)OR″, —C(O)NH₂, —C(O)NHR″, —C(O)N(R″)₂,—NHC(O)R″, —SR″, —SO₃R″, —S(O)₂R″, —S(O)R″, —OH, —N₃, —NH₂, —NH(R″),—N(R″)₂ and —CN, where each R″ is independently selected from —H, —C₁-C₈alkyl, —C₂-C₈ alkenyl, —C₂-C₈ alkynyl, or -aryl.

Examples of monocyclic carbocylic substituents include -cyclopropyl,-cyclobutyl, -cyclopentyl, -1-cyclopent-1-enyl, -1-cyclopent-2-enyl,-1-cyclopent-3-enyl, cyclohexyl, -1-cyclohex-1-enyl, -1-cyclohex-2-enyl,-1-cyclohex-3-enyl, -cycloheptyl, -cyclooctyl. -1,3-cyclohexadienyl,-1,4-cyclohexadienyl, -1,3-cycloheptadienyl, -1,3,5-cycloheptatrienyl,and -cyclooctadienyl.

A “carbocyclo,” whether used alone or as part of another group, refersto an optionally substituted carbocycle group as defined above that isdivalent (i.e., derived by the removal of two hydrogen atoms from thesame or two different carbon atoms of a parent carbocyclic ring system).

Unless otherwise indicated by context, a hyphen (-) designates the pointof attachment to the pendant molecule. Accordingly, the term “—(C₁-C₈alkylene)aryl” or “—C₁-C₈ alkylene(aryl)” refers to a C₁-C₈ alkyleneradical as defined herein wherein the alkylene radical is attached tothe pendant molecule at any of the carbon atoms of the alkylene radicaland one of the hydrogen atoms bonded to a carbon atom of the alkyleneradical is replaced with an aryl radical as defined herein.

When a particular group is “substituted”, that group may have one ormore substituents, preferably from one to five substituents, morepreferably from one to three substituents, most preferably from one totwo substituents, independently selected from the list of substituents.The group can, however, generally have any number of substituentsselected from halogen. Groups that are substituted are so indicated.

It is intended that the definition of any substituent or variable at aparticular location in a molecule be independent of its definitionselsewhere in that molecule. It is understood that substituents andsubstitution patterns on the compounds of this invention can be selectedby one of ordinary skill in the art to provide compounds that arechemically stable and that can be readily synthesized by techniquesknown in the art as well as those methods set forth herein.

Protective groups as used herein refer to groups which selectivelyblock, either temporarily or permanently, one reactive site in amultifunctional compound. Suitable hydroxy-protecting groups for use inthe present invention are pharmaceutically acceptable and may or may notneed to be cleaved from the parent compound after administration to asubject in order for the compound to be active. Cleavage is throughnormal metabolic processes within the body. Hydroxy protecting groupsare well known in the art, see, Protective Groups in Organic Synthesisby T. W. Greene and P. G. M. Wuts (John Wiley & sons, 3^(rd) Edition)incorporated herein by reference in its entirety and for all purposesand include, for example, ether (e.g., alkyl ethers and silyl ethersincluding, for example, dialkylsilylether, trialkylsilylether,dialkylalkoxysilylether), ester, carbonate, carbamates, sulfonate, andphosphate protecting groups. Examples of hydroxy protecting groupsinclude, but are not limited to, methyl ether; methoxymethyl ether,methylthiomethyl ether, (phenyldimethylsilyl)methoxymethyl ether,benzyloxymethyl ether, p-methoxybenzyloxymethyl ether,p-nitrobenzyloxymethyl ether, o-nitrobenzyloxymethyl ether,(4-methoxyphenoxy)methyl ether, guaiacolmethyl ether, t-butoxymethylether, 4-pentenyloxymethyl ether, siloxymethyl ether,2-methoxyethoxymethyl ether, 2,2,2-trichloroethoxymethyl ether,bis(2-chloroethoxy)methyl ether, 2-(trimethylsilyl)ethoxymethyl ether,menthoxymethyl ether, tetrahydropyranyl ether, 1-methoxycylcohexylether, 4-methoxytetrahydrothiopyranyl ether,4-methoxytetrahydrothiopyranyl ether S,S-Dioxide,1-[(2-choro-4-methyl)phenyl]-4-methoxypiperidin-4-yl ether,1-(2-fluorophneyl)-4-methoxypiperidin-4-yl ether, 1,4-dioxan-2-yl ether,tetrahydrofuranyl ether, tetrahydrothiofuranyl ether; substituted ethylethers such as 1-ethoxyethyl ether, 1-(2-chloroethoxy)ethyl ether,1-[2-(trimethylsilyl)ethoxy]ethyl ether, 1-methyl-1-methoxyethyl ether,1-methyl-1-benzyloxyethyl ether, 1-methyl-1-benzyloxy-2-fluoroethylether, 1-methyl-1phenoxyethyl ether, 2-trimethylsilyl ether, t-butylether, allyl ether, propargyl ethers, p-chlorophenyl ether,p-methoxyphenyl ether, benzyl ether, p-methoxybenzyl ether3,4-dimethoxybenzyl ether, trimethylsilyl ether, triethylsilyl ether,tripropylsilylether, dimethylisopropylsilyl ether, diethylisopropylsilylether, dimethylhexylsilyl ether, t-butyldimethylsilyl ether,diphenylmethylsilyl ether, benzoylformate ester, acetate ester,chloroacetate ester, dichloroacetate ester, trichloroacetate ester,trifluoroacetate ester, methoxyacetate ester, triphneylmethoxyacetateester, phenylacetate ester, benzoate ester, alkyl methyl carbonate,alkyl 9-fluorenylmethyl carbonate, alkyl ethyl carbonate, alkyl2,2,2,-trichloroethyl carbonate, 1,1,-dimethyl-2,2,2-trichloroethylcarbonate, alkylsulfonate, methanesulfonate, benzylsulfonate, tosylate,methylene acetal, ethylidene acetal, and t-butylmethylidene ketal.Preferred protecting groups are represented by the formulas —R^(a),—Si(R^(a))(R^(a))(R^(a)), —C(O)R^(a), —C(O)OR^(a), —C(O)NH(R^(a)),—S(O)₂R^(a), —S(O)₂OH, P(O)(OH)₂, and —P(O)(OH)OR^(a), wherein R^(a) isC₁-C₂₀ alkyl, C₂-C₂₀ alkenyl, C₂-C₂₀ alkynyl, —C₁-C₂₀alkylene(carbocycle), —C₂-C₂₀ alkenylene(carbocycle), —C₂-C₂₀alkynylene(carbocycle), —C₆-C₁₀ aryl, —C₁-C₂₀ alkylene(aryl), —C₂-C₂₀alkenylene(aryl), —C₂-C₂₀ alkynylene(aryl), —C₁-C₂₀alkylene(heterocycle), —C₂-C₂₀ alkenylene(heterocycle), or —C₂-C₂₀alkynylene(heterocycle) wherein said alkyl, alkenyl, alkynyl, alkylene,alkenylene, alkynylene, aryl, carbocycle, and heterocycle radicalswhether alone or as part of another group are optionally substituted.

“Altering the native glycosylation pattern” is intended for purposesherein to mean deleting one or more carbohydrate moieties found innative sequence 191P4D12 (either by removing the underlyingglycosylation site or by deleting the glycosylation by chemical and/orenzymatic means), and/or adding one or more glycosylation sites that arenot present in the native sequence 191P4D12. In addition, the phraseincludes qualitative changes in the glycosylation of the nativeproteins, involving a change in the nature and proportions of thevarious carbohydrate moieties present.

The term “analog” refers to a molecule which is structurally similar orshares similar or corresponding attributes with another molecule (e.g. a191P4D12-related protein). For example, an analog of a 191P4D12 proteincan be specifically bound by an antibody or T cell that specificallybinds to 191P4D12.

The term “antibody” is used in the broadest sense unless clearlyindicated otherwise. Therefore, an “antibody” can be naturally occurringor man-made such as monoclonal antibodies produced by conventionalhybridoma technology. 191P4D12 antibodies comprise monoclonal andpolyclonal antibodies as well as fragments containing theantigen-binding domain and/or one or more complementarity determiningregions of these antibodies. As used herein, the term “antibody” refersto any form of antibody or fragment thereof that specifically binds191P4D12 and/or exhibits the desired biological activity andspecifically covers monoclonal antibodies (including full lengthmonoclonal antibodies), polyclonal antibodies, multispecific antibodies(e.g., bispecific antibodies), and antibody fragments so long as theyspecifically bind 191P4D12 and/or exhibit the desired biologicalactivity. Any specific antibody can be used in the methods andcompositions provided herein. Thus, in one embodiment the term“antibody” encompasses a molecule comprising at least one variableregion from a light chain immunoglobulin molecule and at least onevariable region from a heavy chain molecule that in combination form aspecific binding site for the target antigen. In one embodiment, theantibody is an IgG antibody. For example, the antibody is a IgG1, IgG2,IgG3, or IgG4 antibody. The antibodies useful in the present methods andcompositions can be generated in cell culture, in phage, or in variousanimals, including but not limited to cows, rabbits, goats, mice, rats,hamsters, guinea pigs, sheep, dogs, cats, monkeys, chimpanzees, andapes. Therefore, in one embodiment, an antibody of the present inventionis a mammalian antibody. Phage techniques can be used to isolate aninitial antibody or to generate variants with altered specificity oravidity characteristics. Such techniques are routine and well known inthe art. In one embodiment, the antibody is produced by recombinantmeans known in the art. For example, a recombinant antibody can beproduced by transfecting a host cell with a vector comprising a DNAsequence encoding the antibody. One or more vectors can be used totransfect the DNA sequence expressing at least one VL and one VH regionin the host cell. Exemplary descriptions of recombinant means ofantibody generation and production include Delves, ANTIBODY PRODUCTION:ESSENTIAL TECHNIQUES (Wiley, 1997); Shephard, et al., MONOCLONALANTIBODIES (Oxford University Press, 2000); Goding, MONOCLONALANTIBODIES: PRINCIPLES AND PRACTICE (Academic Press, 1993); and CURRENTPROTOCOLS IN IMMUNOLOGY (John Wiley & Sons, most recent edition). Anantibody of the present invention can be modified by recombinant meansto increase efficacy of the antibody in mediating the desired function.Thus, it is within the scope of the invention that antibodies can bemodified by substitutions using recombinant means. Typically, thesubstitutions will be conservative substitutions. For example, at leastone amino acid in the constant region of the antibody can be replacedwith a different residue. See, e.g., U.S. Pat. Nos. 5,624,821,6,194,551, Application No. WO 9958572; and Angal, et al., Mol. Immunol.30: 105-08 (1993). The modification in amino acids includes deletions,additions, and substitutions of amino acids. In some cases, such changesare made to reduce undesired activities, e.g., complement-dependentcytotoxicity. Frequently, the antibodies are labeled by joining, eithercovalently or non-covalently, a substance which provides for adetectable signal. A wide variety of labels and conjugation techniquesare known and are reported extensively in both the scientific and patentliterature. These antibodies can be screened for binding to normal ordefective 191P4D12. See e.g., Antibody Engineering: A Practical Approach(Oxford University Press, 1996). Suitable antibodies with the desiredbiologic activities can be identified using the following in vitroassays including but not limited to: proliferation, migration, adhesion,soft agar growth, angiogenesis, cell-cell communication, apoptosis,transport, signal transduction, and the following in vivo assays such asthe inhibition of tumor growth. The antibodies provided herein can alsobe useful in diagnostic applications. As capture or non-neutralizingantibodies, they can be screened for the ability to bind to the specificantigen without inhibiting the receptor-binding or biological activityof the antigen. As neutralizing antibodies, the antibodies can be usefulin competitive binding assays. They can also be used to quantify the191P4D12 or its receptor.

The term “antigen-binding portion” or “antibody fragment” of an antibody(or simply “antibody portion”), as used herein, refers to one or morefragments of a 191P4D12 antibody that retain the ability to specificallybind to an antigen (e.g., 191P4D12 and variants; FIG. 1). It has beenshown that the antigen-binding function of an antibody can be performedby fragments of a full-length antibody. Examples of binding fragmentsencompassed within the term “antigen-binding portion” of an antibodyinclude (i) a Fab fragment, a monovalent fragment consisting of theV_(L), V_(H), C_(L) and C_(H1) domains; (ii) a F(ab′)₂ fragment, abivalent fragment comprising two Fab fragments linked by a disulfidebridge at the hinge region; (iii) a Fd fragment consisting of the V_(H)and C_(H1) domains; (iv) a Fv fragment consisting of the V_(L) and V_(H)domains of a single arm of an antibody, (v) a dAb fragment (Ward et al.,(1989) Nature 341:544-546), which consists of a V_(H) domain; and (vi)an isolated complementarily determining region (CDR). Furthermore,although the two domains of the Fv fragment, V_(L) and V_(H), are codedfor by separate genes, they can be joined, using recombinant methods, bya synthetic linker that enables them to be made as a single proteinchain in which the V_(L) and V_(H) regions pair to form monovalentmolecules (known as single chain Fv (scFv); see e.g., Bird et al. (1988)Science 242:423-426; and Huston et al. (1988) Proc. Natl. Acad. Sci. USA85:5879-5883). Such single chain antibodies are also intended to beencompassed within the term “antigen-binding portion” of an antibody.These antibody fragments are obtained using conventional techniquesknown to those with skill in the art, and the fragments are screened forutility in the same manner as are intact antibodies.

As used herein, any form of the “antigen” can be used to generate anantibody that is specific for 191P4D12. Thus, the eliciting antigen maybe a single epitope, multiple epitopes, or the entire protein alone orin combination with one or more immunogenicity enhancing agents known inthe art. The eliciting antigen may be an isolated full-length protein, acell surface protein (e.g., immunizing with cells transfected with atleast a portion of the antigen), or a soluble protein (e.g., immunizingwith only the extracellular domain portion of the protein). The antigenmay be produced in a genetically modified cell. The DNA encoding theantigen may be genomic or non-genomic (e.g., cDNA) and encodes at leasta portion of the extracellular domain. As used herein, the term“portion” refers to the minimal number of amino acids or nucleic acids,as appropriate, to constitute an immunogenic epitope of the antigen ofinterest. Any genetic vectors suitable for transformation of the cellsof interest may be employed, including but not limited to adenoviralvectors, plasmids, and non-viral vectors, such as cationic lipids. Inone embodiment, the antibody of the methods and compositions hereinspecifically bind at least a portion of the extracellular domain of the191P4D12 of interest.

The antibodies or antigen binding fragments thereof provided herein maybe conjugated to a “bioactive agent.” As used herein, the term“bioactive agent” refers to any synthetic or naturally occurringcompound that binds the antigen and/or enhances or mediates a desiredbiological effect to enhance cell-killing toxins. In one embodiment, thebinding fragments useful in the present invention are biologicallyactive fragments. As used herein, the term “biologically active” refersto an antibody or antibody fragment that is capable of binding thedesired antigenic epitope and directly or indirectly exerting a biologiceffect. Direct effects include, but are not limited to the modulation,stimulation, and/or inhibition of a growth signal, the modulation,stimulation, and/or inhibition of an anti-apoptotic signal, themodulation, stimulation, and/or inhibition of an apoptotic or necroticsignal, modulation, stimulation, and/or inhibition the ADCC cascade, andmodulation, stimulation, and/or inhibition the CDC cascade.

“Bispecific” antibodies are also useful in the present methods andcompositions. As used herein, the term “bispecific antibody” refers toan antibody, typically a monoclonal antibody, having bindingspecificities for at least two different antigenic epitopes. In oneembodiment, the epitopes are from the same antigen. In anotherembodiment, the epitopes are from two different antigens. Methods formaking bispecific antibodies are known in the art. For example,bispecific antibodies can be produced recombinantly using theco-expression of two immunoglobulin heavy chain/light chain pairs. See,e.g., Milstein et al., Nature 305:537-39 (1983). Alternatively,bispecific antibodies can be prepared using chemical linkage. See, e.g.,Brennan, et al., Science 229:81 (1985). Bispecific antibodies includebispecific antibody fragments. See, e.g., Hollinger, et al., Proc. Natl.Acad. Sci. U.S.A. 90:6444-48 (1993), Gruber, et al., J. Immunol.152:5368 (1994).

The monoclonal antibodies described herein specifically include“chimeric” antibodies in which a portion of the heavy and/or light chainis identical with or homologous to corresponding sequences in antibodiesderived from a particular species or belonging to a particular antibodyclass or subclass, while the remainder of the chain(s) is identical withor homologous to corresponding sequences in antibodies derived fromanother species or belonging to another antibody class or subclass, aswell as fragments of such antibodies, so long as they specifically bindthe target antigen and/or exhibit the desired biological activity (U.S.Pat. No. 4,816,567; and Morrison et al., Proc. Natl. Acad. Sci. USA 81:6851-6855 (1984)).

The term “Chemotherapeutic Agent” refers to all chemical compounds thatare effective in inhibiting tumor growth. Non-limiting examples ofchemotherapeutic agents include alkylating agents; for example, nitrogenmustards, ethyleneimine compounds and alkyl sulphonates;antimetabolites, for example, folic acid, purine or pyrimidineantagonists; mitotic inhibitors, for example, anti-tubulin agents suchas vinca alkaloids, auristatins and derivatives of podophyllotoxin;cytotoxic antibiotics; compounds that damage or interfere with DNAexpression or replication, for example, DNA minor groove binders; andgrowth factor receptor antagonists. In addition, chemotherapeutic agentsinclude cytotoxic agents (as defined herein), antibodies, biologicalmolecules and small molecules.

The term “compound” refers to and encompasses the chemical compounditself as well as, whether explicitly stated or not, and unless thecontext makes clear that the following are to be excluded: amorphous andcrystalline forms of the compound, including polymorphic forms, wherethese forms may be part of a mixture or in isolation; free acid and freebase forms of the compound, which are typically the forms shown in thestructures provided herein; isomers of the compound, which refers tooptical isomers, and tautomeric isomers, where optical isomers includeenantiomers and diastereomers, chiral isomers and non-chiral isomers,and the optical isomers include isolated optical isomers as well asmixtures of optical isomers including racemic and non-racemic mixtures;where an isomer may be in isolated form or in a mixture with one or moreother isomers; isotopes of the compound, including deuterium- andtritium-containing compounds, and including compounds containingradioisotopes, including therapeutically- and diagnostically-effectiveradioisotopes; multimeric forms of the compound, including dimeric,trimeric, etc. forms; salts of the compound, preferably pharmaceuticallyacceptable salts, including acid addition salts and base addition salts,including salts having organic counterions and inorganic counterions,and including zwitterionic forms, where if a compound is associated withtwo or more counterions, the two or more counterions may be the same ordifferent; and solvates of the compound, including hemisolvates,monosolvates, disolvates, etc., including organic solvates and inorganicsolvates, said inorganic solvates including hydrates; where if acompound is associated with two or more solvent molecules, the two ormore solvent molecules may be the same or different. In some instances,reference made herein to a compound of the invention will include anexplicit reference to one or of the above forms, e.g., salts and/orsolvates; however, this reference is for emphasis only, and is not to beconstrued as excluding other of the above forms as identified above.

As used herein, the term “conservative substitution” refers tosubstitutions of amino acids are known to those of skill in this art andmay be made generally without altering the biological activity of theresulting molecule. Those of skill in this art recognize that, ingeneral, single amino acid substitutions in non-essential regions of apolypeptide do not substantially alter biological activity (see, e.g.,Watson, et al., MOLECULAR BIOLOGY OF THE GENE, The Benjamin/CummingsPub. Co., p. 224 (4th Edition 1987)). Such exemplary substitutions arepreferably made in accordance with those set forth in Table II andTable(s) III(a-b). For example, such changes include substituting any ofisoleucine (I), valine (V), and leucine (L) for any other of thesehydrophobic amino acids; aspartic acid (D) for glutamic acid (E) andvice versa; glutamine (Q) for asparagine (N) and vice versa; and serine(S) for threonine (T) and vice versa. Other substitutions can also beconsidered conservative, depending on the environment of the particularamino acid and its role in the three-dimensional structure of theprotein. For example, glycine (G) and alanine (A) can frequently beinterchangeable, as can alanine (A) and valine (V). Methionine (M),which is relatively hydrophobic, can frequently be interchanged withleucine and isoleucine, and sometimes with valine. Lysine (K) andarginine (R) are frequently interchangeable in locations in which thesignificant feature of the amino acid residue is its charge and thediffering pK's of these two amino acid residues are not significant.Still other changes can be considered “conservative” in particularenvironments (see, e.g. Table III(a) herein; pages 13-15 “Biochemistry”2nd ED. Lubert Stryer ed (Stanford University); Henikoff et al., PNAS1992 Vol 89 10915-10919; Lei et al., J Biol Chem 1995 May 19;270(20):11882-11886). Other substitutions are also permissible and maybe determined empirically or in accord with known conservativesubstitutions.

The term “cytotoxic agent” refers to a substance that inhibits orprevents the expression activity of cells, function of cells and/orcauses destruction of cells. The term is intended to include radioactiveisotopes, chemotherapeutic agents, and toxins such as small moleculetoxins or enzymatically active toxins of bacterial, fungal, plant oranimal origin, including fragments and/or variants thereof. Examples ofcytotoxic agents include, but are not limited to auristatins (e.g.,auristatin E, auristatin F, MMAE and MMAF), auromycins, maytansinoids,ricin, ricin A-chain, combrestatin, duocarmycins, dolastatins,doxorubicin, daunorubicin, taxols, cisplatin, cc1065, ethidium bromide,mitomycin, etoposide, tenoposide, vincristine, vinblastine, colchicine,dihydroxy anthracin dione, actinomycin, diphtheria toxin, Pseudomonasexotoxin (PE) A, PE40, abrin, abrin A chain, modeccin A chain,alpha-sarcin, gelonin, mitogellin, retstrictocin, phenomycin, enomycin,curicin, crotin, calicheamicin, Sapaonaria officinalis inhibitor, andglucocorticoid and other chemotherapeutic agents, as well asradioisotopes such as At²¹¹, I¹³¹, I¹²⁵, Y⁹⁰, Re¹⁸⁶, Re¹⁸⁸, Sm¹⁵³, Bi²¹²or ²¹³, P³² and radioactive isotopes of Lu including Lu¹⁷⁷. Antibodiesmay also be conjugated to an anti-cancer pro-drug activating enzymecapable of converting the pro-drug to its active form.

As used herein, the term “diabodies” refers to small antibody fragmentswith two antigen-binding sites, which fragments comprise a heavy chainvariable domain (V_(H)) connected to a light chain variable domain(V_(L)) in the same polypeptide chain (V_(H)-V_(L)). By using a linkerthat is too short to allow pairing between the two domains on the samechain, the domains are forced to pair with the complementary domains ofanother chain and create two antigen-binding sites. Diabodies aredescribed more fully in, e.g., EP 404,097; WO 93/11161; and Hollinger etal., Proc. Natl. Acad. Sci. USA 90:6444-48 (1993).

The term “deplete,” in the context of the effect of a 191P4D12 bindingagent on 191P4D12-expressing cells, refers to a reduction in the numberof or elimination of the 191P4D12-expressing cells.

The term “gene product” is used herein to indicate a peptide/protein ormRNA. For example, a “gene product of the invention” is sometimesreferred to herein as a “cancer amino acid sequence”, “cancer protein”,“protein of a cancer listed in Table I”, a “cancer mRNA”, “mRNA of acancer listed in Table I”, etc. In one embodiment, the cancer protein isencoded by a nucleic acid of FIG. 1. The cancer protein can be afragment, or alternatively, be the full-length protein encoded bynucleic acids of FIG. 1. In one embodiment, a cancer amino acid sequenceis used to determine sequence identity or similarity. In anotherembodiment, the sequences are naturally occurring allelic variants of aprotein encoded by a nucleic acid of FIG. 1. In another embodiment, thesequences are sequence variants as further described herein.

“Heteroconjugate” antibodies are useful in the present methods andcompositions. As used herein, the term “heteroconjugate antibody” refersto two covalently joined antibodies. Such antibodies can be preparedusing known methods in synthetic protein chemistry, including usingcrosslinking agents. See, e.g., U.S. Pat. No. 4,676,980.

The term “homolog” refers to a molecule which exhibits homology toanother molecule, by for example, having sequences of chemical residuesthat are the same or similar at corresponding positions.

In one embodiment, the antibody provided herein is a “human antibody.”As used herein, the term “human antibody” refers to an antibody in whichessentially the entire sequences of the light chain and heavy chainsequences, including the complementary determining regions (CDRs), arefrom human genes. In one embodiment, human monoclonal antibodies areprepared by the trioma technique, the human B-cell technique (see, e.g.,Kozbor, et al., Immunol. Today 4: 72 (1983), EBV transformationtechnique (see, e.g., Cole et al. Monoclonal Antibodies And CancerTherapy 77-96 (1985)), or using phage display (see, e.g., Marks et al.,J. Mol. Biol. 222:581 (1991)). In a specific embodiment, the humanantibody is generated in a transgenic mouse. Techniques for making suchpartially to fully human antibodies are known in the art and any suchtechniques can be used. According to one particularly preferredembodiment, fully human antibody sequences are made in a transgenicmouse engineered to express human heavy and light chain antibody genes.An exemplary description of preparing transgenic mice that produce humanantibodies found in Application No. WO 02/43478 and U.S. Pat. No.6,657,103 (Abgenix) and its progeny. B cells from transgenic mice thatproduce the desired antibody can then be fused to make hybridoma celllines for continuous production of the antibody. See, e.g., U.S. Pat.Nos. 5,569,825; 5,625,126; 5,633,425; 5,661,016; and 5,545,806; andJakobovits, Adv. Drug Del. Rev. 31:33-42 (1998); Green, et al., J. Exp.Med. 188:483-95 (1998).

As used herein, the term “humanized antibody” refers to forms ofantibodies that contain sequences from non-human (e.g., murine)antibodies as well as human antibodies. Such antibodies are chimericantibodies which contain minimal sequence derived from non-humanimmunoglobulin. In general, the humanized antibody will comprisesubstantially all of at least one, and typically two, variable domains,in which all or substantially all of the hypervariable loops correspondto those of a non-human immunoglobulin and all or substantially all ofthe FR regions are those of a human immunoglobulin sequence. Thehumanized antibody optionally also will comprise at least a portion ofan immunoglobulin constant region (Fc), typically that of a humanimmunoglobulin. See e.g., Cabilly U.S. Pat. No. 4,816,567; Queen et al.(1989) Proc. Nat'l Acad. Sci. USA 86:10029-10033; and AntibodyEngineering: A Practical Approach (Oxford University Press 1996).

The terms “inhibit” or “inhibition of” as used herein means to reduce bya measurable amount, or to prevent entirely.

The phrases “isolated” or “biologically pure” refer to material which issubstantially or essentially free from components which normallyaccompany the material as it is found in its native state. Thus,isolated peptides in accordance with the invention preferably do notcontain materials normally associated with the peptides in their in situenvironment. For example, a polynucleotide is said to be “isolated” whenit is substantially separated from contaminant polynucleotides thatcorrespond or are complementary to genes other than the 191P4D12 genesor that encode polypeptides other than 191P4D12 gene product orfragments thereof. A skilled artisan can readily employ nucleic acidisolation procedures to obtain an isolated 191P4D12 polynucleotide. Aprotein is said to be “isolated,” for example, when physical, mechanicalor chemical methods are employed to remove the 191P4D12 proteins fromcellular constituents that are normally associated with the protein. Askilled artisan can readily employ standard purification methods toobtain an isolated 191P4D12 protein. Alternatively, an isolated proteincan be prepared by chemical means.

Suitable “labels” include radionuclides, enzymes, substrates, cofactors,inhibitors, fluorescent moieties, chemiluminescent moieties, magneticparticles, and the like. Patents teaching the use of such labels includeU.S. Pat. Nos. 3,817,837; 3,850,752; 3,939,350; 3,996,345; 4,277,437;4,275,149; and 4,366,241. In addition, the antibodies provided hereincan be useful as the antigen-binding component of fluorobodies. Seee.g., Zeytun et al., Nat. Biotechnol. 21:1473-79 (2003).

The term “mammal” refers to any organism classified as a mammal,including mice, rats, rabbits, dogs, cats, cows, horses and humans. Inone embodiment of the invention, the mammal is a mouse. In anotherembodiment of the invention, the mammal is a human.

The terms “metastatic cancer” and “metastatic disease” mean cancers thathave spread to regional lymph nodes or to distant sites, and are meantto include stage D disease under the AUA system and stage T×N×M+ underthe TNM system.

The term “modulator” or “test compound” or “drug candidate” orgrammatical equivalents as used herein describe any molecule, e.g.,protein, oligopeptide, small organic molecule, polysaccharide,polynucleotide, etc., to be tested for the capacity to directly orindirectly alter the cancer phenotype or the expression of a cancersequence, e.g., a nucleic acid or protein sequences, or effects ofcancer sequences (e.g., signaling, gene expression, protein interaction,etc.) In one aspect, a modulator will neutralize the effect of a cancerprotein of the invention. By “neutralize” is meant that an activity of aprotein is inhibited or blocked, along with the consequent effect on thecell. In another aspect, a modulator will neutralize the effect of agene, and its corresponding protein, of the invention by normalizinglevels of said protein. In preferred embodiments, modulators alterexpression profiles, or expression profile nucleic acids or proteinsprovided herein, or downstream effector pathways. In one embodiment, themodulator suppresses a cancer phenotype, e.g. to a normal tissuefingerprint. In another embodiment, a modulator induced a cancerphenotype. Generally, a plurality of assay mixtures is run in parallelwith different agent concentrations to obtain a differential response tothe various concentrations. Typically, one of these concentrationsserves as a negative control, i.e., at zero concentration or below thelevel of detection.

Modulators, drug candidates, or test compounds encompass numerouschemical classes, though typically they are organic molecules,preferably small organic compounds having a molecular weight of morethan 100 and less than about 2,500 Daltons. Preferred small moleculesare less than 2000, or less than 1500 or less than 1000 or less than 500D. Candidate agents comprise functional groups necessary for structuralinteraction with proteins, particularly hydrogen bonding, and typicallyinclude at least an amine, carbonyl, hydroxyl or carboxyl group,preferably at least two of the functional chemical groups. The candidateagents often comprise cyclical carbon or heterocyclic structures and/oraromatic or polyaromatic structures substituted with one or more of theabove functional groups. Modulators also comprise biomolecules such aspeptides, saccharides, fatty acids, steroids, purines, pyrimidines,derivatives, structural analogs or combinations thereof. Particularlypreferred are peptides. One class of modulators are peptides, forexample of from about five to about 35 amino acids, with from about fiveto about 20 amino acids being preferred, and from about 7 to about 15being particularly preferred. Preferably, the cancer modulatory proteinis soluble, includes a non-transmembrane region, and/or, has anN-terminal Cys to aid in solubility. In one embodiment, the C-terminusof the fragment is kept as a free acid and the N-terminus is a freeamine to aid in coupling, i.e., to cysteine. In one embodiment, a cancerprotein of the invention is conjugated to an immunogenic agent asdiscussed herein. In one embodiment, the cancer protein is conjugated toBSA. The peptides of the invention, e.g., of preferred lengths, can belinked to each other or to other amino acids to create a longerpeptide/protein. The modulatory peptides can be digests of naturallyoccurring proteins as is outlined above, random peptides, or “biased”random peptides. In a preferred embodiment, peptide/protein-basedmodulators are antibodies, and fragments thereof, as defined herein.

The term “monoclonal antibody”, as used herein, refers to an antibodyobtained from a population of substantially homogeneous antibodies,i.e., the individual antibodies comprising the population are identicalexcept for possible naturally occurring mutations that may be present inminor amounts. Monoclonal antibodies are highly specific, being directedagainst a single antigenic epitope. In contrast, conventional(polyclonal) antibody preparations typically include a multitude ofantibodies directed against (or specific for) different epitopes. In oneembodiment, the polyclonal antibody contains a plurality of monoclonalantibodies with different epitope specificities, affinities, oravidities within a single antigen that contains multiple antigenicepitopes. The modifier “monoclonal” indicates the character of theantibody as being obtained from a substantially homogeneous populationof antibodies, and is not to be construed as requiring production of theantibody by any particular method. For example, the monoclonalantibodies to be used in accordance with the present invention may bemade by the hybridoma method first described by Kohler et al., Nature256: 495 (1975), or may be made by recombinant DNA methods (see, e.g.,U.S. Pat. No. 4,816,567). The “monoclonal antibodies” may also beisolated from phage antibody libraries using the techniques described inClackson et al., Nature 352: 624-628 (1991) and Marks et al., J. Mol.Biol. 222: 581-597 (1991), for example. These monoclonal antibodies willusually bind with at least a Kd of about 1 μM, more usually at leastabout 300 nM, typically at least about 30 nM, preferably at least about10 nM, more preferably at least about 3 nM or better, usually determinedby ELISA.

A “pharmaceutical excipient” comprises a material such as an adjuvant, acarrier, pH-adjusting and buffering agents, tonicity adjusting agents,wetting agents, preservative, and the like.

“Pharmaceutically acceptable” refers to a non-toxic, inert, and/orcomposition that is physiologically compatible with humans or othermammals.

The term “polynucleotide” means a polymeric form of nucleotides of atleast 10 bases or base pairs in length, either ribonucleotides ordeoxynucleotides or a modified form of either type of nucleotide, and ismeant to include single and double stranded forms of DNA and/or RNA. Inthe art, this term if often used interchangeably with “oligonucleotide”.A polynucleotide can comprise a nucleotide sequence disclosed hereinwherein thymidine (T), as shown for example in FIG. 1, can also beuracil (U); this definition pertains to the differences between thechemical structures of DNA and RNA, in particular the observation thatone of the four major bases in RNA is uracil (U) instead of thymidine(T).

The term “polypeptide” means a polymer of at least about 4, 5, 6, 7, or8 amino acids. Throughout the specification, standard three letter orsingle letter designations for amino acids are used. In the art, thisterm is often used interchangeably with “peptide” or “protein”.

A “recombinant” DNA or RNA molecule is a DNA or RNA molecule that hasbeen subjected to molecular manipulation in vitro.

As used herein, the term “single-chain Fv” or “scFv” or “single chain”antibody refers to antibody fragments comprising the V_(H) and V_(L)domains of antibody, wherein these domains are present in a singlepolypeptide chain. Generally, the Fv polypeptide further comprises apolypeptide linker between the V_(H) and V_(L) domains which enables thesFv to form the desired structure for antigen binding. For a review ofsFv, see Pluckthun, The Pharmacology Of Monoclonal Antibodies, vol. 113,Rosenburg and Moore eds. Springer-Verlag, New York, pp. 269-315 (1994).

As used herein, the terms “specific”, “specifically binds” and “bindsspecifically” refer to the selective binding of the antibody to thetarget antigen epitope. Antibodies can be tested for specificity ofbinding by comparing binding to appropriate antigen to binding toirrelevant antigen or antigen mixture under a given set of conditions.If the antibody binds to the appropriate antigen at least 2, 5, 7, andpreferably 10 times more than to irrelevant antigen or antigen mixturethen it is considered to be specific. In one embodiment, a specificantibody is one that only binds the 191P4D12 antigen, but does not bindto the irrelevant antigen. In another embodiment, a specific antibody isone that binds human 191P4D12 antigen but does not bind a non-human191P4D12 antigen with 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%,96%, 97%, 98%, 99% or greater amino acid homology with the 191P4D12antigen. In another embodiment, a specific antibody is one that bindshuman 191 P4D 12 antigen and binds murine 191 P4D 12 antigen, but with ahigher degree of binding the human antigen. In another embodiment, aspecific antibody is one that binds human 191P4D12 antigen and bindsprimate 191P4D12 antigen, but with a higher degree of binding the humanantigen. In another embodiment, the specific antibody binds to human191P4D12 antigen and any non-human 191P4D12 antigen, but with a higherdegree of binding the human antigen or any combination thereof.

As used herein “to treat” or “therapeutic” and grammatically relatedterms, refer to any improvement of any consequence of disease, such asprolonged survival, less morbidity, and/or a lessening of side effectswhich are the byproducts of an alternative therapeutic modality; as isreadily appreciated in the art, full eradication of disease is apreferred but albeit not a requirement for a treatment act.

The term “variant” refers to a molecule that exhibits a variation from adescribed type or norm, such as a protein that has one or more differentamino acid residues in the corresponding position(s) of a specificallydescribed protein (e.g. the 191P4D12 protein shown in FIG. 1.) An analogis an example of a variant protein. Splice isoforms and singlenucleotides polymorphisms (SNPs) are further examples of variants.

The “191P4D12 proteins” and/or “191P4D12 related proteins” of theinvention include those specifically identified herein (see, FIG. 1), aswell as allelic variants, conservative substitution variants, analogsand homologs that can be isolated/generated and characterized withoutundue experimentation following the methods outlined herein or readilyavailable in the art. Fusion proteins that combine parts of different191P4D12 proteins or fragments thereof, as well as fusion proteins of a191P4D12 protein and a heterologous polypeptide are also included. Such191P4D12 proteins are collectively referred to as the 191P4D12-relatedproteins, the proteins of the invention, or 191P4D12. The term“191P4D12-related protein” refers to a polypeptide fragment or a191P4D12 protein sequence of 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15,16, 17, 18, 19, 20, 21, 22, 23, 24, 25, or more than 25 amino acids; or,at least 30, 35, 40, 45, 50, 55, 60, 65, 70, 80, 85, 90, 95, 100, 105,110, 115, 120, 125, 130, 135, 140, 145, 150, 155, 160, 165, 170, 175,180, 185, 190, 195, 200, 225, 250, 275, 300, 325, 330, 335, 339 or moreamino acids.

II.) 191P4D12 Antibodies

Another aspect of the invention provides antibodies that bind to191P4D12-related proteins (See FIG. 1). In one embodiment, the antibodythat binds to 191P4D12-related proteins is an antibody that specificallybinds to 191P4D12 protein comprising amino acid sequence of SEQ ID NO.:2. The antibody that specifically binds to 191P4D12 protein comprisingamino acid sequence of SEQ ID NO.: 2 includes antibodies that can bindto other 191P4D12-related proteins. For example, antibodies that bind191P4D12 protein comprising amino acid sequence of SEQ ID NO.:2 can bind191P4D12-related proteins such as 191P4D12 variants and the homologs oranalogs thereof.

191P4D12 antibodies of the invention are particularly useful in cancer(see, e.g., Table I) prognostic assays, imaging, and therapeuticmethodologies. Similarly, such antibodies are useful in the treatment,and/or prognosis of colon and other cancers, to the extent 191P4D12 isalso expressed or overexpressed in these other cancers. Moreover,intracellularly expressed antibodies (e.g., single chain antibodies) aretherapeutically useful in treating cancers in which the expression of191P4D12 is involved, such as advanced or metastatic colon cancers orother advanced or metastatic cancers.

Various methods for the preparation of antibodies, specificallymonoclonal antibodies, are well known in the art. For example,antibodies can be prepared by immunizing a suitable mammalian host usinga 191P4D12-related protein, peptide, or fragment, in isolated orimmunoconjugated form (Antibodies: A Laboratory Manual, CSH Press, Eds.,Harlow, and Lane (1988); Harlow, Antibodies, Cold Spring Harbor Press,NY (1989)). In addition, fusion proteins of 191P4D12 can also be used,such as a 191P4D12 GST-fusion protein. In a particular embodiment, a GSTfusion protein comprising all or most of the amino acid sequence of FIG.1 is produced, and then used as an immunogen to generate appropriateantibodies. In another embodiment, a 191P4D12-related protein issynthesized and used as an immunogen.

In addition, naked DNA immunization techniques known in the art are used(with or without purified 191P4D12-related protein or 191P4D12expressing cells) to generate an immune response to the encodedimmunogen (for review, see Donnelly et al., 1997, Ann. Rev. Immunol. 15:617-648).

The amino acid sequence of a 191P4D12 protein as shown in FIG. 1 can beanalyzed to select specific regions of the 191P4D12 protein forgenerating antibodies. For example, hydrophobicity and hydrophilicityanalyses of a 191P4D12 amino acid sequence are used to identifyhydrophilic regions in the 191P4D12 structure. Regions of a 191P4D12protein that show immunogenic structure, as well as other regions anddomains, can readily be identified using various other methods known inthe art, such as Chou-Fasman, Garnier-Robson, Kyte-Doolittle, Eisenberg,Karplus-Schultz or Jameson-Wolf analysis. Hydrophilicity profiles can begenerated using the method of Hopp, T. P. and Woods, K. R., 1981, Proc.Natl. Acad. Sci. U.S.A. 78:3824-3828. Hydropathicity profiles can begenerated using the method of Kyte, J. and Doolittle, R. F., 1982, J.Mol. Biol. 157:105-132. Percent (%) Accessible Residues profiles can begenerated using the method of Janin J., 1979, Nature 277:491-492.Average Flexibility profiles can be generated using the method ofBhaskaran R., Ponnuswamy P. K., 1988, Int. J. Pept. Protein Res.32:242-255. Beta-turn profiles can be generated using the method ofDeleage, G., Roux B., 1987, Protein Engineering 1:289-294. Thus, eachregion identified by any of these programs or methods is within thescope of the present invention. Preferred methods for the generation of191P4D12 antibodies are further illustrated by way of the examplesprovided herein. Methods for preparing a protein or polypeptide for useas an immunogen are well known in the art. Also well known in the artare methods for preparing immunogenic conjugates of a protein with acarrier, such as BSA, KLH or other carrier protein. In somecircumstances, direct conjugation using, for example, carbodiimidereagents are used; in other instances linking reagents such as thosesupplied by Pierce Chemical Co., Rockford, Ill., are effective.Administration of a 191P4D12 immunogen is often conducted by injectionover a suitable time period and with use of a suitable adjuvant, as isunderstood in the art. During the immunization schedule, titers ofantibodies can be taken to determine adequacy of antibody formation.

191P4D12 monoclonal antibodies can be produced by various means wellknown in the art. For example, immortalized cell lines that secrete adesired monoclonal antibody are prepared using the standard hybridomatechnology of Kohler and Milstein or modifications that immortalizeantibody-producing B cells, as is generally known. Immortalized celllines that secrete the desired antibodies are screened by immunoassay inwhich the antigen is a 191P4D12-related protein. When the appropriateimmortalized cell culture is identified, the cells can be expanded andantibodies produced either from in vitro cultures or from ascites fluid.

The antibodies or fragments of the invention can also be produced byrecombinant means. Regions that bind specifically to the desired regionsof a 191P4D12 protein can also be produced in the context of chimeric orcomplementarity-determining region (CDR) grafted antibodies of multiplespecies origin. Humanized or human 191P4D12 antibodies can also beproduced, and are preferred for use in therapeutic contexts. Methods forhumanizing murine and other non-human antibodies, by substituting one ormore of the non-human antibody CDRs for corresponding human antibodysequences, are well known (see for example, Jones et al., 1986, Nature321: 522-525; Riechmann et al., 1988, Nature 332: 323-327; Verhoeyen etal., 1988, Science 239: 1534-1536). See also, Carter et al., 1993, Proc.Natl. Acad. Sci. USA 89: 4285 and Sims et al., 1993, J. Immunol. 151:2296.

In a preferred embodiment, the antibodies of the present inventioncomprise fully human 191P4D12 antibodies (191P4D12 MAbs). Variousmethods in the art provide means for producing fully human 191P4D12MAbs. For example, a preferred embodiment provides for techniques usingtransgenic mice, inactivated for antibody production, engineered withhuman heavy and light chains loci referred to as Xenomouse (AmgenFremont, Inc.). An exemplary description of preparing transgenic micethat produce human antibodies can be found in U.S. Pat. No. 6,657,103.See, also, U.S. Pat. Nos. 5,569,825; 5,625,126; 5,633,425; 5,661,016;and 5,545,806; and Mendez, et. al. Nature Genetics, 15: 146-156 (1998);Kellerman, S. A. & Green, L. L., Curr. Opin. Biotechnol 13, 593-597(2002).

In addition, human antibodies of the invention can be generated usingthe HuMAb mouse (Medarex, Inc.) which contains human immunoglobulin geneminiloci that encode unrearranged human heavy (mu and gamma) and kappalight chain immunoglobulin sequences, together with targeted mutationsthat inactivate the endogenous mu and kappa chain loci (see e.g.,Lonberg, et al. (1994) Nature 368(6474): 856-859).

In another embodiment, fully human antibodies of the invention can beraised using a mouse that carries human immunoglobulin sequences ontransgenes and transchomosomes, such as a mouse that carries a humanheavy chain transgene and a human light chain transchromosome. Suchmice, referred to herein as “KM mice”, such mice are described inTomizuka et al. (2000) Proc. Natl. Acad. Sci. USA 97:722-727 and PCTPublication WO 02/43478 to Tomizuka, et al.

Human monoclonal antibodies of the invention can also be prepared usingphage display methods for screening libraries of human immunoglobulingenes. Such phage display methods for isolating human antibodies areestablished in the art. See for example: U.S. Pat. Nos. 5,223,409;5,403,484; and 5,571,698 to Ladner et al.; U.S. Pat. Nos. 5,427,908 and5,580,717 to Dower et al.; U.S. Pat. Nos. 5,969,108 and 6,172,197 toMcCafferty et al.; and U.S. Pat. Nos. 5,885,793; 6,521,404; 6,544,731;6,555,313; 6,582,915 and 6,593,081 to Griffiths et al.

Human monoclonal antibodies of the invention can also be prepared usingSCID mice into which human immune cells have been reconstituted suchthat a human antibody response can be generated upon immunization. Suchmice are described in, for example, U.S. Pat. Nos. 5,476,996 and5,698,767 to Wilson et al.

In a preferred embodiment, an 191P4D12 MAbs of the invention comprisesheavy and light chain variable regions of an antibody designatedHa22-2(2,4)6.1 produced by a hybridoma deposited under the American TypeCulture Collection (ATCC) Accession No.: PTA-11267 (See, FIG. 3), orheavy and light variable regions comprising amino acid sequences thatare homologous to the amino acid sequences of the heavy and light chainvariable regions of Ha22-2(2,4)6.1, and wherein the antibodies retainthe desired functional properties of the 191P4D12 MAbs of the invention.The heavy chain variable region of Ha22-2(2,4)6.1 consists of the aminoacid sequence ranging from 20^(th) E residue to the 136^(th) S residueof SEQ ID NO:7, and the light chain variable region of Ha22-2(2,4)6.1consists of the amino acid sequence ranging from 23^(rd) D residue tothe 130^(th) R residue of SEQ ID NO:8. As the constant region of theantibody of the invention, any subclass of constant region can bechosen. In one embodiment, human IgG1 constant region as the heavy chainconstant region and human Ig kappa constant region as the light chainconstant region can be used.

For example, the invention provides an isolated monoclonal antibody, orantigen binding portion thereof, comprising a heavy chain variableregion and a light chain variable region, wherein:

(a) the heavy chain variable region comprises an amino acid sequencethat is at least 80% homologous to heavy chain variable region aminoacid sequence set forth in FIG. 3; and

(b) the light chain variable region comprises an amino acid sequencethat is at least 80% homologous to the light chain variable region aminoacid sequence set forth in FIG. 3.

In other embodiments, the V_(H) and/or V_(L) amino acid sequences may be85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or99% homologous to the V_(H) and V_(L) sequences set forth in FIG. 3.

In another embodiment, the invention provides an isolated monoclonalantibody, or antigen binding portion thereof, comprising a humanizedheavy chain variable region and a humanized light chain variable region,wherein:

(a) the heavy chain variable region comprises complementaritydetermining regions (CDRs) having the amino acid sequences of the heavychain variable region CDRs set forth in FIG. 3;

(b) the light chain variable region comprises CDRs having the amino acidsequences of the light chain variable region CDRs set forth in FIG. 3.

Engineered antibodies of the invention include those in whichmodifications have been made to framework residues within V_(H) and/orV_(L) (e.g. to improve the properties of the antibody). Typically suchframework modifications are made to decrease the immunogenicity of theantibody. For example, one approach is to “backmutate” one or moreframework residues to the corresponding germline sequence. Morespecifically, an antibody that has undergone somatic mutation maycontain framework residues that differ from the germline sequence fromwhich the antibody is derived. Such residues can be identified bycomparing the antibody framework sequences to the germline sequencesfrom which the antibody is derived. To return the framework regionsequences to their germline configuration, the somatic mutations can be“backmutated” to the germline sequence by, for example, site-directedmutagenesis or PCR-mediated mutagenesis (e.g., “backmutated” fromleucine to methionine). Such “backmutated” antibodies are also intendedto be encompassed by the invention.

Another type of framework modification involves mutating one or moreresidues within the framework region, or even within one or more CDRregions, to remove T-cell epitopes to thereby reduce the potentialimmunogenicity of the antibody. This approach is also referred to as“deimmunization” and is described in further detail in U.S. PatentPublication No. 2003/0153043 by Carr et al.

In addition or alternative to modifications made within the framework orCDR regions, antibodies of the invention may be engineered to includemodifications within the Fc region, typically to alter one or morefunctional properties of the antibody, such as serum half-life,complement fixation, Fc receptor binding, and/or antigen-dependentcellular cytotoxicity. Furthermore, a 191P4D12 MAb of the invention maybe chemically modified (e.g., one or more chemical moieties can beattached to the antibody) or be modified to alter its glycosylation,again to alter one or more functional properties of the MAb. Each ofthese embodiments is described in further detail below.

In one embodiment, the hinge region of CH1 is modified such that thenumber of cysteine residues in the hinge region is altered, e.g.,increased or decreased. This approach is described further in U.S. Pat.No. 5,677,425 by Bodmer et al. The number of cysteine residues in thehinge region of CH1 is altered to, for example, facilitate assembly ofthe light and heavy chains or to increase or decrease the stability ofthe 191P4D12 MAb.

In another embodiment, the Fc hinge region of an antibody is mutated todecrease the biological half life of the 191P4D12 MAb. Morespecifically, one or more amino acid mutations are introduced into theCH2-CH3 domain interface region of the Fc-hinge fragment such that theantibody has impaired Staphylococcyl protein A (SpA) binding relative tonative Fc-hinge domain SpA binding. This approach is described infurther detail in U.S. Pat. No. 6,165,745 by Ward et al.

In another embodiment, the 191P4D12 MAb is modified to increase itsbiological half life. Various approaches are possible. For example,mutations can be introduced as described in U.S. Pat. No. 6,277,375 toWard. Alternatively, to increase the biological half life, the antibodycan be altered within the CH1 or CL region to contain a salvage receptorbinding epitope taken from two loops of a CH2 domain of an Fc region ofan IgG, as described in U.S. Pat. Nos. 5,869,046 and 6,121,022 by Prestaet al.

In yet other embodiments, the Fc region is altered by replacing at leastone amino acid residue with a different amino acid residue to alter theeffector function(s) of the 191P4D12 MAb. For example, one or more aminoacids selected from amino acid specific residues can be replaced with adifferent amino acid residue such that the antibody has an alteredaffinity for an effector ligand but retains the antigen-binding abilityof the parent antibody. The effector ligand to which affinity is alteredcan be, for example, an Fc receptor or the C1 component of complement.This approach is described in further detail in U.S. Pat. Nos. 5,624,821and 5,648,260, both by Winter et al.

Reactivity of 191P4D12 antibodies with a 191P4D12-related protein can beestablished by a number of well known means, including Western blot,immunoprecipitation, ELISA, and FACS analyses using, as appropriate,191P4D12-related proteins, 191P4D12-expressing cells or extractsthereof. A 191P4D12 antibody or fragment thereof can be labeled with adetectable marker or conjugated to a second molecule. Suitabledetectable markers include, but are not limited to, a radioisotope, afluorescent compound, a bioluminescent compound, chemiluminescentcompound, a metal chelator or an enzyme. Further, bi-specific antibodiesspecific for two or more 191P4D12 epitopes are generated using methodsgenerally known in the art. Homodimeric antibodies can also be generatedby cross-linking techniques known in the art (e.g., Wolff et al., CancerRes. 53: 2560-2565).

In yet another preferred embodiment, the 191P4D12 MAb of the inventionis an antibody comprising heavy and light chain of an antibodydesignated Ha22-2(2,4)6.1. The heavy chain of Ha22-2(2,4)6.1 consists ofthe amino acid sequence ranging from 20^(th) E residue to the 466^(th) Kresidue of SEQ ID NO:7 and the light chain of Ha22-2(2,4)6.1 consists ofamino acid sequence ranging from 23^(rd) D residue to the 236^(th) Cresidue of SEQ ID NO:8 sequence. The sequence of which is set forth inFIG. 2 and FIG. 3. In a preferred embodiment, Ha22-2(2,4)6.1 isconjugated to a cytotoxic agent.

The hybridoma producing the antibody designated Ha22-2(2,4)6.1 was sent(via Federal Express) to the American Type Culture Collection (ATCC),P.O. Box 1549, Manassas, Va. 20108 on 18 Aug. 2010 and assignedAccession number PTA-11267.

III.) Antibody-Drug Conjugates Generally

In another aspect, the invention provides antibody-drug conjugates(ADCs), comprising an antibody conjugated to a cytotoxic agent such as achemotherapeutic agent, a drug, a growth inhibitory agent, a toxin(e.g., an enzymatically active toxin of bacterial, fungal, plant, oranimal origin, or fragments thereof), or a radioactive isotope (i.e., aradioconjugate). In another aspect, the invention further providesmethods of using the ADCs. In one aspect, an ADC comprises any of theherein 191P4D12 MAbs covalently attached to a cytotoxic agent or adetectable agent.

The use of antibody-drug conjugates for the local delivery of cytotoxicor cytostatic agents, i.e. drugs to kill or inhibit tumor cells in thetreatment of cancer (Syrigos and Epenetos (1999) Anticancer Research19:605-614; Niculescu-Duvaz and Springer (1997) Adv. Drg Del. Rev.26:151-172; U.S. Pat. No. 4,975,278) allows targeted delivery of thedrug moiety to tumors, and intracellular accumulation therein, wheresystemic administration of these unconjugated drug agents may result inunacceptable levels of toxicity to normal cells as well as the tumorcells sought to be eliminated (Baldwin et al., (1986) Lancet pp. (Mar.15, 1986):603-05; Thorpe, (1985) “Antibody Carriers Of Cytotoxic AgentsIn Cancer Therapy: A Review,” in Monoclonal Antibodies '84: BiologicalAnd Clinical Applications, A. Pinchera et al. (ed.s), pp. 475-506).Maximal efficacy with minimal toxicity is sought thereby. Bothpolyclonal antibodies and monoclonal antibodies have been reported asuseful in these strategies (Rowland et al., (1986) Cancer Immunol.Immunother., 21:183-87). Drugs used in these methods include daunomycin,doxorubicin, methotrexate, and vindesine (Rowland et al., (1986) supra).Toxins used in antibody-toxin conjugates include bacterial toxins suchas diphtheria toxin, plant toxins such as ricin, small molecule toxinssuch as geldanamycin (Mandler et al (2000) Jour. of the Nat. CancerInst. 92(19):1573-1581; Mandler et al (2000) Bioorganic & Med. Chem.Letters 10:1025-1028; Mandler et al (2002) Bioconjugate Chem.13:786-791), maytansinoids (EP 1391213; Liu et al., (1996) Proc. Natl.Acad. Sci. USA 93:8618-8623), and calicheamicin (Lode et al (1998)Cancer Res. 58:2928; Hinman et al (1993) Cancer Res. 53:3336-3342). Thetoxins may assert their cytotoxic and cytostatic effects by mechanismsincluding tubulin binding, DNA binding, or topoisomerase inhibition.Some cytotoxic drugs tend to be inactive or less active when conjugatedto large antibodies or protein receptor ligands.

Examples of antibody drug conjugates are, ZEVALIN® (ibritumomabtiuxetan, Biogen/Idec) which is an antibody-radioisotope conjugatecomposed of a murine IgG1 kappa monoclonal antibody directed against theCD20 antigen found on the surface of normal and malignant B lymphocytesand ¹¹¹In or ⁹⁰Y radioisotope bound by a thiourea linker-chelator(Wiseman et al (2000) Eur. Jour. Nucl. Med. 27(7):766-77; Wiseman et al(2002) Blood 99(12):4336-42; Witzig et al (2002) J. Clin. Oncol.20(10):2453-63; Witzig et al (2002) J. Clin. Oncol. 20(15):3262-69).

Additionally, MYLOTARG™ (gemtuzumab ozogamicin, Wyeth Pharmaceuticals),an antibody drug conjugate composed of a hu CD33 antibody linked tocalicheamicin, was approved in 2000 for the treatment of acute myeloidleukemia by injection (Drugs of the Future (2000) 25(7):686; U.S. Pat.Nos. 4,970,198; 5,079,233; 5,585,089; 5,606,040; 5,693,762; 5,739,116;5,767,285; 5,773,001).

In addition, Cantuzumab mertansine (Immunogen, Inc.), an antibody drugconjugate composed of the huC242 antibody linked via the disulfidelinker SPP to the maytansinoid drug moiety, DM1, is advancing into PhaseII trials for the treatment of cancers that express CanAg, such ascolon, pancreatic, gastric, and others.

Additionally, MLN-2704 (Millennium Pharm., BZL Biologics, ImmunogenInc.), an antibody drug conjugate composed of the anti-prostate specificmembrane antigen (PSMA) monoclonal antibody linked to the maytansinoiddrug moiety, DM1, is under development for the potential treatment ofprostate tumors.

Finally, the auristatin peptides, auristatin E (AE) andmonomethylauristatin (MMAE), synthetic analogs of dolastatin, wereconjugated to chimeric monoclonal antibodies cBR96 (specific to Lewis Yon carcinomas) and cAC10 (specific to CD30 on hematologicalmalignancies) (Doronina et al (2003) Nature Biotechnology 21(7):778-784)and are under therapeutic development.

Further, chemotherapeutic agents useful in the generation of ADCs aredescribed herein. Enzymatically active toxins and fragments thereof thatcan be used include diphtheria A chain, nonbinding active fragments ofdiphtheria toxin, exotoxin A chain (from Pseudomonas aeruginosa), ricinA chain, abrin A chain, modeccin A chain, alpha-sarcin, Aleurites fordiiproteins, dianthin proteins, Phytolaca americana proteins (PAPI, PAPII,and PAP-S), momordica charantia inhibitor, curcin, crotin, sapaonariaofficinalis inhibitor, gelonin, mitogellin, restrictocin, phenomycin,enomycin, and the tricothecenes. See, e.g., WO 93/21232 published Oct.28, 1993. A variety of radionuclides are available for the production ofradioconjugated antibodies. Examples include ²¹²Bi, ¹³¹I, ¹³¹In, ⁹⁰Y,and ¹⁸⁶Re. Conjugates of the antibody and cytotoxic agent are made usinga variety of bifunctional protein-coupling agents such asN-succinimidyl-3-(2-pyridyldithiol)propionate (SPDP), iminothiolane(IT), bifunctional derivatives of imidoesters (such as dimethyladipimidate HCl), active esters (such as disuccinimidyl suberate),aldehydes (such as glutaraldehyde), bis-azido compounds (such asbis(p-azidobenzoyl)hexanediamine), bis-diazonium derivatives (such asbis-(p-diazoniumbenzoyl)-ethylenediamine), diisocyanates (such astoluene 2,6-diisocyanate), and bis-active fluorine compounds (such as1,5-difluoro-2,4-dinitrobenzene). For example, a ricin immunotoxin canbe prepared as described in Vitetta et al (1987) Science, 238:1098.Carbon-14-labeled 1-isothiocyanatobenzyl-3-methyldiethylenetriaminepentaacetic acid (MX-DTPA) is an exemplary chelating agent forconjugation of radionucleotide to the antibody (WO94/11026).

Conjugates of an antibody and one or more small molecule toxins, such asa calicheamicin, maytansinoids, dolastatins, auristatins, atrichothecene, and CC1065, and the derivatives of these toxins that havetoxin activity, are also contemplated herein.

III(A). Maytansinoids

Maytansine compounds suitable for use as maytansinoid drug moieties arewell known in the art, and can be isolated from natural sourcesaccording to known methods, produced using genetic engineeringtechniques (see Yu et al (2002) PNAS 99:7968-7973), or maytansinol andmaytansinol analogues prepared synthetically according to known methods.

Exemplary maytansinoid drug moieties include those having a modifiedaromatic ring, such as: C-19-dechloro (U.S. Pat. No. 4,256,746)(prepared by lithium aluminum hydride reduction of ansamytocin P2);C-20-hydroxy (or C-20-demethyl) +/−C-19-dechloro (U.S. Pat. Nos.4,361,650 and 4,307,016) (prepared by demethylation using Streptomycesor Actinomyces or dechlorination using LAH); and C-20-demethoxy,C-20-acyloxy (—OCOR), +/−dechloro (U.S. Pat. No. 4,294,757) (prepared byacylation using acyl chlorides), and those having modifications at otherpositions

Exemplary maytansinoid drug moieties also include those havingmodifications such as: C-9-SH (U.S. Pat. No. 4,424,219) (prepared by thereaction of maytansinol with H₂5 or P₂S₅);C-14-alkoxymethyl(demethoxy/CH₂OR) (U.S. Pat. No. 4,331,598);C-14-hydroxymethyl or acyloxymethyl (CH₂OH or CH₂OAc) (U.S. Pat. No.4,450,254) (prepared from Nocardia); C-15-hydroxy/acyloxy (U.S. Pat. No.4,364,866) (prepared by the conversion of maytansinol by Streptomyces);C-15-methoxy (U.S. Pat. Nos. 4,313,946 and 4,315,929) (isolated fromTrewia nudlflora); C-18-N-demethyl (U.S. Pat. Nos. 4,362,663 and4,322,348) (prepared by the demethylation of maytansinol byStreptomyces); and 4,5-deoxy (U.S. Pat. No. 4,371,533) (prepared by thetitanium trichloride/LAH reduction of maytansinol).

ADCs containing maytansinoids, methods of making same, and theirtherapeutic use are disclosed, for example, in U.S. Pat. Nos. 5,208,020;5,416,064; 6,441,163 and European Patent EP 0 425 235 B1, thedisclosures of which are hereby expressly incorporated by reference. Liuet al., Proc. Natl. Acad. Sci. USA 93:8618-8623 (1996) described ADCscomprising a maytansinoid designated DM1 linked to the monoclonalantibody C242 directed against human colorectal cancer. The conjugatewas found to be highly cytotoxic towards cultured colon cancer cells,and showed antitumor activity in an in vivo tumor growth assay. Chari etal., Cancer Research 52:127-131 (1992) describe ADCs in which amaytansinoid was conjugated via a disulfide linker to the murineantibody A7 binding to an antigen on human colon cancer cell lines, orto another murine monoclonal antibody TA.1 that binds the HER-2/neuoncogene. The cytotoxicity of the TA.1-maytansonoid conjugate was testedin vitro on the human breast cancer cell line SK-BR-3, which expresses3×10⁵ HER-2 surface antigens per cell. The drug conjugate achieved adegree of cytotoxicity similar to the free maytansinoid drug, whichcould be increased by increasing the number of maytansinoid moleculesper antibody molecule. The A7-maytansinoid conjugate showed low systemiccytotoxicity in mice.

III(B). Auristatins and Dolastatins

In some embodiments, the ADC comprises an antibody of the inventionconjugated to dolastatins or dolostatin peptidic analogs andderivatives, the auristatins (U.S. Pat. Nos. 5,635,483; 5,780,588).Dolastatins and auristatins have been shown to interfere withmicrotubule dynamics, GTP hydrolysis, and nuclear and cellular division(Woyke et al (2001) Antimicrob. Agents and Chemother. 45(12):3580-3584)and have anticancer (U.S. Pat. No. 5,663,149) and antifungal activity(Pettit et al (1998) Antimicrob. Agents Chemother. 42:2961-2965). Thedolastatin or auristatin drug moiety may be attached to the antibodythrough the N (amino) terminus or the C (carboxyl) terminus of thepeptidic drug moiety (WO 02/088172).

Exemplary auristatin embodiments include the N-terminus linkedmonomethylauristatin drug moieties DE and DF, disclosed in “Senter etal, Proceedings of the American Association for Cancer Research, Volume45, Abstract Number 623, presented Mar. 28, 2004 and described in UnitedStates Patent Publication No. 2005/0238649, the disclosure of which isexpressly incorporated by reference in its entirety.

An exemplary auristatin embodiment is MMAE (wherein the wavy lineindicates the covalent attachment to a linker (L) of an antibody drugconjugate).

Another exemplary auristatin embodiment is MMAF, wherein the wavy lineindicates the covalent attachment to a linker (L) of an antibody drugconjugate (US 2005/0238649):

Additional exemplary embodiments comprising MMAE or MMAF and variouslinker components (described further herein) have the followingstructures and abbreviations (wherein Ab means antibody, S is a sulfurof the antibody, and p is 1 to about 8):

Typically, peptide-based drug moieties can be prepared by forming apeptide bond between two or more amino acids and/or peptide fragments.Such peptide bonds can be prepared, for example, according to the liquidphase synthesis method (see E. Schröder and K. Lübke, “The Peptides”,volume 1, pp 76-136, 1965, Academic Press) that is well known in thefield of peptide chemistry. The auristatin/dolastatin drug moieties maybe prepared according to the methods of: U.S. Pat. Nos. 5,635,483;5,780,588; Pettit et al (1989) J. Am. Chem. Soc. 111:5463-5465; Pettitet al (1998) Anti-Cancer Drug Design 13:243-277; Pettit, G. R., et al.Synthesis, 1996, 719-725; Pettit et al (1996) J. Chem. Soc. PerkinTrans. 1 5:859-863; and Doronina (2003) Nat Biotechnol 21(7):778-784.

III(C). Calicheamicin

In other embodiments, the ADC comprises an antibody of the inventionconjugated to one or more calicheamicin molecules. The calicheamicinfamily of antibiotics are capable of producing double-stranded DNAbreaks at sub-picomolar concentrations. For the preparation ofconjugates of the calicheamicin family, see U.S. Pat. Nos. 5,712,374,5,714,586, 5,739,116, 5,767,285, 5,770,701, 5,770,710, 5,773,001,5,877,296 (all to American Cyanamid Company). Structural analogues ofcalicheamicin which may be used include, but are not limited to, γ₁ ¹,α₂ ¹, α₃ ¹, N-acetyl-γ₁ ¹, PSAG and θ¹ ₁ (Hinman et al., Cancer Research53:3336-3342 (1993), Lode et al., Cancer Research 58:2925-2928 (1998)and the aforementioned U.S. patents to American Cyanamid). Anotheranti-tumor drug that the antibody can be conjugated is QFA which is anantifolate. Both calicheamicin and QFA have intracellular sites ofaction and do not readily cross the plasma membrane. Therefore, cellularuptake of these agents through antibody mediated internalization greatlyenhances their cytotoxic effects.

III(D). Other Cytotoxic Agents

Other antitumor agents that can be conjugated to the antibodies of theinvention include BCNU, streptozoicin, vincristine and 5-fluorouracil,the family of agents known collectively LL-E33288 complex described inU.S. Pat. Nos. 5,053,394, 5,770,710, as well as esperamicins (U.S. Pat.No. 5,877,296).

Enzymatically active toxins and fragments thereof which can be usedinclude diphtheria A chain, nonbinding active fragments of diphtheriatoxin, exotoxin A chain (from Pseudomonas aeruginosa), ricin A chain,abrin A chain, modeccin A chain, alpha-sarcin, Aleurites fordiiproteins, dianthin proteins, Phytolaca americana proteins (PAPI, PAPII,and PAP-S), momordica charantia inhibitor, curcin, crotin, sapaonariaofficinalis inhibitor, gelonin, mitogellin, restrictocin, phenomycin,enomycin and the tricothecenes. See, for example, WO 93/21232 publishedOct. 28, 1993.

The present invention further contemplates an ADC formed between anantibody and a compound with nucleolytic activity (e.g., a ribonucleaseor a DNA endonuclease such as a deoxyribonuclease; DNase).

For selective destruction of the tumor, the antibody may comprise ahighly radioactive atom. A variety of radioactive isotopes are availablefor the production of radioconjugated antibodies. Examples includeAt²¹¹, I¹³¹, I¹²⁵, Y⁹⁰, Re¹⁸⁶, Re¹⁸⁸, Sm¹⁵³, Bi²¹², P³², Pb²¹² andradioactive isotopes of Lu. When the conjugate is used for detection, itmay comprise a radioactive atom for scintigraphic studies, for exampletc^(99m) or I¹²³, or a spin label for nuclear magnetic resonance (NMR)imaging (also known as magnetic resonance imaging, mri), such asiodine-123 again, iodine-131, indium-111, fluorine-19, carbon-13,nitrogen-15, oxygen-17, gadolinium, manganese or iron.

The radio- or other labels may be incorporated in the conjugate in knownways. For example, the peptide may be biosynthesized or may besynthesized by chemical amino acid synthesis using suitable amino acidprecursors involving, for example, fluorine-19 in place of hydrogen.Labels such as tc^(99m) or I¹²³, Re¹⁸⁶, Re¹⁸⁸ and In¹¹¹ can be attachedvia a cysteine residue in the peptide. Yttrium-90 can be attached via alysine residue. The IODOGEN method (Fraker et al (1978) Biochem.Biophys. Res. Commun 80: 49-57 can be used to incorporate iodine-123.“Monoclonal Antibodies in Immunoscintigraphy” (Chatal, CRC Press 1989)describes other methods in detail.

IV.) Antibody-Drug Conjugate Compounds Which Bind 191P4D12

The present invention provides, inter alia, antibody-drug conjugatecompounds for targeted delivery of drugs. The inventors have made thediscovery that the antibody-drug conjugate compounds have potentcytotoxic and/or cytostatic activity against cells expressing 191P4D12.The antibody-drug conjugate compounds comprise an Antibody unitcovalently linked to at least one Drug unit. The Drug units can becovalently linked directly or via a Linker unit (LU).

In some embodiments, the antibody drug conjugate compound has thefollowing formula:L-(LU-D)_(p)   (I)

-   -   or a pharmaceutically acceptable salt or solvate thereof;        wherein:    -   L is the Antibody unit, e.g., 191P4D12 MAb of the present        invention, and    -   (LU-D) is a Linker unit-Drug unit moiety, wherein:    -   LU- is a Linker unit, and    -   -D is a drug unit having cytostatic or cytotoxic activity        against a target cell; and    -   p is an integer from 1 to 20.

In some embodiments, p ranges from 1 to 10, 1 to 9, 1 to 8, 1 to 7, 1 to6, 1 to 5, 1 to 4, 1 to 3, or 1 to 2. In some embodiments, p ranges from2 to 10, 2 to 9, 2 to 8, 2 to 7, 2 to 6, 2 to 5, 2 to 4 or 2 to 3. Inother embodiments, p is 1, 2, 3, 4, 5 or 6. In some embodiments, p is 2or 4.

In some embodiments, the antibody drug conjugate compound has thefollowing formula:L-(A_(a)-W_(w)—Y_(y)-D)_(p)   (II)

-   -   or a pharmaceutically acceptable salt or solvate thereof,        wherein:    -   L is the Antibody unit, e.g., 191P4D12 MAb; and    -   -A_(a)-W_(w)—Y_(y)— is a Linker unit (LU), wherein:    -   -A- is a Stretcher unit,    -   a is 0 or 1,    -   each —W— is independently an Amino Acid unit,    -   w is an integer ranging from 0 to 12,    -   —Y— is a self-immolative spacer unit,    -   y is 0, 1 or 2;    -   -D is a drug units having cytostatic or cytotoxic activity        against the target cell; and    -   p is an integer from 1 to 20.

In some embodiments, a is 0 or 1, w is 0 or 1, and y is 0, 1 or 2. Insome embodiments, a is 0 or 1, w is 0 or 1, and y is 0 or 1. In someembodiments, p ranges from 1 to 10, 1 to 9, 1 to 8, 1 to 7, 1 to 6, 1 to5, 1 to 4, 1 to 3, or 1 to 2. In some embodiments, p ranges from 2 to 8,2 to 7, 2 to 6, 2 to 5, 2 to 4 or 2 to 3. In other embodiments, p is 1,2, 3, 4, 5 or 6. In some embodiments, p is 2 or 4. In some embodiments,when w is not zero, y is 1 or 2. In some embodiments, when w is 1 to 12,y is 1 or 2. In some embodiments, w is 2 to 12 and y is 1 or 2. In someembodiments, a is 1 and w and y are 0.

For compositions comprising a plurality antibodies, the drug loading isrepresented by p, the average number of drug molecules per Antibody.Drug loading may range from 1 to 20 drugs (D) per Antibody. The averagenumber of drugs per antibody in preparation of conjugation reactions maybe characterized by conventional means such as mass spectroscopy, ELISAassay, and HPLC. The quantitative distribution ofAntibody-Drug-Conjugates in terms of p may also be determined. In someinstances, separation, purification, and characterization of homogeneousAntibody-Drug-conjugates where p is a certain value fromAntibody-Drug-Conjugates with other drug loadings may be achieved bymeans such as reverse phase HPLC or electrophoresis. In exemplaryembodiments, p is from 2 to 8.

The generation of Antibody-drug conjugate compounds can be accomplishedby any technique known to the skilled artisan. Briefly, theAntibody-drug conjugate compounds comprise 191P4D12 MAb as the Antibodyunit, a drug, and optionally a linker that joins the drug and thebinding agent. In a preferred embodiment, the Antibody is 191P4D12 MAbcomprising heavy and light chain variable regions of an antibodydesignated Ha22-2(2,4)6.1 described above. In more preferred embodiment,the Antibody is 191P4D12 MAb comprising heavy and light chain of anantibody designated Ha22-2(2,4)6.1 described above. A number ofdifferent reactions are available for covalent attachment of drugsand/or linkers to binding agents. This is often accomplished by reactionof the amino acid residues of the binding agent, e.g., antibodymolecule, including the amine groups of lysine, the free carboxylic acidgroups of glutamic and aspartic acid, the sulfhydryl groups of cysteineand the various moieties of the aromatic amino acids. One of the mostcommonly used non-specific methods of covalent attachment is thecarbodiimide reaction to link a carboxy (or amino) group of a compoundto amino (or carboxy) groups of the antibody. Additionally, bifunctionalagents such as dialdehydes or imidoesters have been used to link theamino group of a compound to amino groups of an antibody molecule. Alsoavailable for attachment of drugs to binding agents is the Schiff basereaction. This method involves the periodate oxidation of a drug thatcontains glycol or hydroxy groups, thus forming an aldehyde which isthen reacted with the binding agent. Attachment occurs via formation ofa Schiff base with amino groups of the binding agent. Isothiocyanatescan also be used as coupling agents for covalently attaching drugs tobinding agents. Other techniques are known to the skilled artisan andwithin the scope of the present invention.

In certain embodiments, an intermediate, which is the precursor of thelinker, is reacted with the drug under appropriate conditions. Incertain embodiments, reactive groups are used on the drug and/or theintermediate. The product of the reaction between the drug and theintermediate, or the derivatized drug, is subsequently reacted with the191P4D12 MAb under appropriate conditions.

Each of the particular units of the Antibody-drug conjugate compounds isdescribed in more detail herein. The synthesis and structure ofexemplary Linker units, Stretcher units, Amino Acid units,self-immolative Spacer unit, and Drug units are also described in U.S.Patent Application Publication Nos. 2003-0083263, 2005-0238649 and2005-0009751, each if which is incorporated herein by reference in itsentirety and for all purposes.

V.) Linker Units

Typically, the antibody-drug conjugate compounds comprise a Linker unitbetween the drug unit and the antibody unit. In some embodiments, thelinker is cleavable under intracellular conditions, such that cleavageof the linker releases the drug unit from the antibody in theintracellular environment. In yet other embodiments, the linker unit isnot cleavable and the drug is released, for example, by antibodydegradation.

In some embodiments, the linker is cleavable by a cleaving agent that ispresent in the intracellular environment (e.g., within a lysosome orendosome or caveolea). The linker can be, e.g., a peptidyl linker thatis cleaved by an intracellular peptidase or protease enzyme, including,but not limited to, a lysosomal or endosomal protease. In someembodiments, the peptidyl linker is at least two amino acids long or atleast three amino acids long. Cleaving agents can include cathepsins Band D and plasmin, all of which are known to hydrolyze dipeptide drugderivatives resulting in the release of active drug inside target cells(see, e.g., Dubowchik and Walker, 1999, Pharm. Therapeutics 83:67-123).Most typical are peptidyl linkers that are cleavable by enzymes that arepresent in 191P4D12-expressing cells. For example, a peptidyl linkerthat is cleavable by the thiol-dependent protease cathepsin-B, which ishighly expressed in cancerous tissue, can be used (e.g., a Phe-Leu or aGly-Phe-Leu-Gly linker (SEQ ID NO:9)). Other examples of such linkersare described, e.g., in U.S. Pat. No. 6,214,345, incorporated herein byreference in its entirety and for all purposes. In a specificembodiment, the peptidyl linker cleavable by an intracellular proteaseis a Val-Cit linker or a Phe-Lys linker (see, e.g., U.S. Pat. No.6,214,345, which describes the synthesis of doxorubicin with the Val-Citlinker). One advantage of using intracellular proteolytic release of thetherapeutic agent is that the agent is typically attenuated whenconjugated and the serum stabilities of the conjugates are typicallyhigh.

In other embodiments, the cleavable linker is pH-sensitive, i.e.,sensitive to hydrolysis at certain pH values. Typically, thepH-sensitive linker hydrolyzable under acidic conditions. For example,an acid-labile linker that is hydrolyzable in the lysosome (e.g., ahydrazone, semicarbazone, thiosemicarbazone, cis-aconitic amide,orthoester, acetal, ketal, or the like) can be used. (See, e.g., U.S.Pat. Nos. 5,122,368; 5,824,805; 5,622,929; Dubowchik and Walker, 1999,Pharm. Therapeutics 83:67-123; Neville et al., 1989, Biol. Chem.264:14653-14661.) Such linkers are relatively stable under neutral pHconditions, such as those in the blood, but are unstable at below pH 5.5or 5.0, the approximate pH of the lysosome. In certain embodiments, thehydrolyzable linker is a thioether linker (such as, e.g., a thioetherattached to the therapeutic agent via an acylhydrazone bond (see, e.g.,U.S. Pat. No. 5,622,929).

In yet other embodiments, the linker is cleavable under reducingconditions (e.g., a disulfide linker). A variety of disulfide linkersare known in the art, including, for example, those that can be formedusing SATA (N-succinimidyl-S-acetylthioacetate), SPDP(N-succinimidyl-3-(2-pyridyldithio)propionate), SPDB(N-succinimidyl-3-(2-pyridyldithio)butyrate) and SMPT(N-succinimidyl-oxycarbonyl-alpha-methyl-alpha-(2-pyridyl-dithio)toluene),SPDB and SMPT. (See, e.g., Thorpe et al., 1987, Cancer Res.47:5924-5931; Wawrzynczak et al., In Immunoconjugates: AntibodyConjugates in Radioimagery and Therapy of Cancer (C. W. Vogel ed.,Oxford U. Press, 1987. See also U.S. Pat. No. 4,880,935.)

In yet other specific embodiments, the linker is a malonate linker(Johnson et al., 1995, Anticancer Res. 15:1387-93), a maleimidobenzoyllinker (Lau et al., 1995, Bioorg-Med-Chem. 3(10):1299-1304), or a3′-N-amide analog (Lau et al., 1995, Bioorg-Med-Chem. 3(10): 1305-12).

In yet other embodiments, the linker unit is not cleavable and the drugis released by antibody degradation. (See U.S. Publication No.2005/0238649 incorporated by reference herein in its entirety and forall purposes).

Typically, the linker is not substantially sensitive to theextracellular environment. As used herein, “not substantially sensitiveto the extracellular environment,” in the context of a linker, meansthat no more than about 20%, typically no more than about 15%, moretypically no more than about 10%, and even more typically no more thanabout 5%, no more than about 3%, or no more than about 1% of thelinkers, in a sample of antibody-drug conjugate compound, are cleavedwhen the antibody-drug conjugate compound presents in an extracellularenvironment (e.g., in plasma). Whether a linker is not substantiallysensitive to the extracellular environment can be determined, forexample, by incubating with plasma the antibody-drug conjugate compoundfor a predetermined time period (e.g., 2, 4, 8, 16, or 24 hours) andthen quantitating the amount of free drug present in the plasma.

In other, non-mutually exclusive embodiments, the linker promotescellular internalization. In certain embodiments, the linker promotescellular internalization when conjugated to the therapeutic agent (i.e.,in the milieu of the linker-therapeutic agent moiety of theantibody-drug conjugate compound as described herein). In yet otherembodiments, the linker promotes cellular internalization whenconjugated to both the auristatin compound and the 191P4D12 MAb.

A variety of exemplary linkers that can be used with the presentcompositions and methods are described in WO 2004-010957, U.S.Publication No. 2006/0074008, U.S. Publication No. 20050238649, and U.S.Publication No. 2006/0024317 (each of which is incorporated by referenceherein in its entirety and for all purposes).

A “Linker unit” (LU) is a bifunctional compound that can be used to linka Drug unit and an Antibody unit to form an antibody-drug conjugatecompound. In some embodiments, the Linker unit has the formula:-A_(a)-W_(w)—Y_(y)—

-   -   wherein: -A- is a Stretcher unit,    -   a is 0 or 1,    -   each —W— is independently an Amino Acid unit,    -   w is an integer ranging from 0 to 12,    -   —Y— is a self-immolative Spacer unit, and    -   y is 0, 1 or 2.

In some embodiments, a is 0 or 1, w is 0 or 1, and y is 0, 1 or 2. Insome embodiments, a is 0 or 1, w is 0 or 1, and y is 0 or 1. In someembodiments, when w is 1 to 12, y is 1 or 2. In some embodiments, w is 2to 12 and y is 1 or 2. In some embodiments, a is 1 and w and y are 0.

VI.) The Stretcher Unit

The Stretcher unit (A), when present, is capable of linking an Antibodyunit to an Amino Acid unit (—W—), if present, to a Spacer unit (—Y—), ifpresent; or to a Drug unit (-D). Useful functional groups that can bepresent on a 191P4D12 MAb (e.g. Ha22-2(2,4)6.1), either naturally or viachemical manipulation include, but are not limited to, sulfhydryl,amino, hydroxyl, the anomeric hydroxyl group of a carbohydrate, andcarboxyl. Suitable functional groups are sulfhydryl and amino. In oneexample, sulfhydryl groups can be generated by reduction of theintramolecular disulfide bonds of a 191P4D12 MAb. In another embodiment,sulfhydryl groups can be generated by reaction of an amino group of alysine moiety of a 191P4D12 MAb with 2-iminothiolane (Traut's reagent)or other sulfhydryl generating reagents. In certain embodiments, the191P4D12 MAb is a recombinant antibody and is engineered to carry one ormore lysines. In certain other embodiments, the recombinant 191P4D12 MAbis engineered to carry additional sulfhydryl groups, e.g., additionalcysteines.

In one embodiment, the Stretcher unit forms a bond with a sulfur atom ofthe Antibody unit. The sulfur atom can be derived from a sulfhydrylgroup of an antibody. Representative Stretcher units of this embodimentare depicted within the square brackets of Formulas IIIa and IIIb,wherein L-, —W—, —Y—, -D, w and y are as defined above, and R¹⁷ isselected from —C₁-C₁₀ alkylene-, —C₁-C₁₀ alkenylene-, —C₁-C₁₀alkynylene-, carbocyclo-, —O—(C₁-C₈ alkylene)-, O—(C₁-C₈ alkenylene)-,—O—(C₁-C₈ alkynylene)-, -arylene-, —C₁-C₁₀ alkylene-arylene-, —C₂-C₁₀alkenylene-arylene, —C₂-C₁₀ alkynylene-arylene, -arylene-C₁-C₁₀alkylene-, -arylene-C₂-C₁₀ alkenylene-, -arylene-C₂-C₁₀ alkynylene-,—C₁-C₁₀ alkylene-(carbocyclo)-, —C₂-C₁₀ alkenylene-(carbocyclo)-,—C₂-C₁₀ alkynylene-(carbocyclo)-, -(carbocyclo)-C₁-C₁₀ alkylene-,-(carbocyclo)-C₂-C₁₀ alkenylene-, -(carbocyclo)-C₂-C₁₀ alkynylene,-heterocyclo-, —C₁-C₁₀ alkylene-(heterocyclo)-, —C₂-C₁₀alkenylene-(heterocyclo)-, —C₂-C₁₀ alkynylene-(heterocyclo)-,-(heterocyclo)-C₁-C₁₀ alkylene-, -(heterocyclo)-C₂-C₁₀ alkenylene-,-(heterocyclo)-C₁-C₁₀ alkynylene-, —(CH₂CH₂O)_(r)—, or—(CH₂CH₂O)_(r)—CH₂—, and r is an integer ranging from 1-10, wherein saidalkyl, alkenyl, alkynyl, alkylene, alkenylene, alkynyklene, aryl,carbocycle, carbocyclo, heterocyclo, and arylene radicals, whether aloneor as part of another group, are optionally substituted. In someembodiments, said alkyl, alkenyl, alkynyl, alkylene, alkenylene,alkynyklene, aryl, carbocyle, carbocyclo, heterocyclo, and aryleneradicals, whether alone or as part of another group, are unsubstituted.In some embodiments, R¹⁷ is selected from —C₁-C₁₀ alkylene-,-carbocyclo-, —O—(C₁-C₈ alkylene)-, -arylene-, —C₁-C₁₀alkylene-arylene-, -arylene-C₁-C₁₀ alkylene-, —C₁-C₁₀alkylene-(carbocyclo)-, -(carbocyclo)-C₁-C₁₀ alkylene-, —C₃-C₈heterocyclo-, —C₁-C₁₀ alkylene-(heterocyclo)-, -(heterocyclo)-C₁-C₁₀alkylene-, —(CH₂CH₂O)_(r)—, and —(CH₂CH₂O)_(r)—CH₂—; and r is an integerranging from 1-10, wherein said alkylene groups are unsubstituted andthe remainder of the groups are optionally substituted.

It is to be understood from all the exemplary embodiments that evenwhere not denoted expressly, from 1 to 20 drug moieties can be linked toan Antibody (p=1-20).

An illustrative Stretcher unit is that of Formula IIIa wherein R¹⁷ is—(CH₂)₅—:

Another illustrative Stretcher unit is that of Formula IIIa wherein R¹⁷is —(CH₂CH₂O)_(r)—CH₂—; and r is 2:

An illustrative Stretcher unit is that of Formula IIIa wherein R¹⁷ isarylene- or arylene-C₁-C₁₀ alkylene-. In some embodiments, the arylgroup is an unsubstituted phenyl group.

Still another illustrative Stretcher unit is that of Formula IIIbwherein R¹⁷ is —(CH₂)₅—:

In certain embodiments, the Stretcher unit is linked to the Antibodyunit via a disulfide bond between a sulfur atom of the Antibody unit anda sulfur atom of the Stretcher unit. A representative Stretcher unit ofthis embodiment is depicted within the square brackets of Formula IV,wherein R¹⁷, L-, —W—, —Y—, -D, w and y are as defined above.

It should be noted that throughout this application, the S moiety in theformula below refers to a sulfur atom of the Antibody unit, unlessotherwise indicated by context.

In yet other embodiments, the Stretcher contains a reactive site thatcan form a bond with a primary or secondary amino group of an Antibody.Examples of these reactive sites include, but are not limited to,activated esters such as succinimide esters, 4 nitrophenyl esters,pentafluorophenyl esters, tetrafluorophenyl esters, anhydrides, acidchlorides, sulfonyl chlorides, isocyanates and isothiocyanates.Representative Stretcher units of this embodiment are depicted withinthe square brackets of Formulas Va and Vb, wherein —R¹⁷—, L-, —W—, —Y—,-D, w and y are as defined above;

In some embodiments, the Stretcher contains a reactive site that isreactive to a modified carbohydrate's (—CHO) group that can be presenton an Antibody. For example, a carbohydrate can be mildly oxidized usinga reagent such as sodium periodate and the resulting (—CHO) unit of theoxidized carbohydrate can be condensed with a Stretcher that contains afunctionality such as a hydrazide, an oxime, a primary or secondaryamine, a hydrazine, a thiosemicarbazone, a hydrazine carboxylate, and anarylhydrazide such as those described by Kaneko et al., 1991,Bioconjugate Chem. 2:133-41. Representative Stretcher units of thisembodiment are depicted within the square brackets of Formulas VIa, VIb,and VIc, wherein —R¹⁷—, L-, —W—, —Y—, -D, w and y are as defined asabove.

VII.) The Amino Acid Unit

The Amino Acid unit (—W—), when present, links the Stretcher unit to theSpacer unit if the Spacer unit is present, links the Stretcher unit tothe Drug moiety if the Spacer unit is absent, and links the Antibodyunit to the Drug unit if the Stretcher unit and Spacer unit are absent.

W_(w)— can be, for example, a monopeptide, dipeptide, tripeptide,tetrapeptide, pentapeptide, hexapeptide, heptapeptide, octapeptide,nonapeptide, decapeptide, undecapeptide or dodecapeptide unit. Each —W—unit independently has the formula denoted below in the square brackets,and w is an integer ranging from 0 to 12:

wherein R¹⁹ is hydrogen, methyl, isopropyl, isobutyl, sec-butyl, benzyl,p-hydroxybenzyl, —CH₂OH, —CH(OH)CH₃, —CH₂CH₂SCH₃, —CH₂CONH₂, —CH₂COOH,—CH₂CH₂CONH₂, —CH₂CH₂COOH, —(CH₂)₃NHC(═NH)NH₂, —(CH₂)₃NH₂,—(CH₂)₃NHCOCH₃, —(CH₂)₃NHCHO, —(CH₂)₄NHC(═NH)NH₂, —(CH₂)₄NH₂,—(CH₂)₄NHCOCH₃, —(CH₂)₄NHCHO, —(CH₂)₃NHCONH₂, —(CH₂)₄NHCONH₂,—CH₂CH₂CH(OH)CH₂NH₂, 2-pyridylmethyl-, 3-pyridylmethyl-,4-pyridylmethyl-, phenyl, cyclohexyl,

In some embodiments, the Amino Acid unit can be enzymatically cleaved byone or more enzymes, including a cancer or tumor-associated protease, toliberate the Drug unit (-D), which in one embodiment is protonated invivo upon release to provide a Drug (D).

In certain embodiments, the Amino Acid unit can comprise natural aminoacids. In other embodiments, the Amino Acid unit can comprisenon-natural amino acids. Illustrative Ww units are represented byformulas (VII)-(IX):

-   -   wherein R²° and R²¹ are as follows:

R²⁰ R²¹ Benzyl (CH₂)₄NH₂; methyl (CH₂)₄NH₂; isopropyl (CH₂)₄NH₂;isopropyl (CH₂)₃NHCONH₂; benzyl (CH₂)₃NHCONH₂; isobutyl (CH₂)₃NHCONH₂;sec-butyl (CH₂)₃NHCONH₂; (CH₂)₃NHCONH₂;

benzyl methyl; benzyl (CH₂)₃NHC(═NH)NH₂;

-   -   wherein R²⁰, R²¹ and R²² are as follows:

R²⁰ R²¹ R²² benzyl benzyl (CH₂)₄NH₂; isopropyl benzyl (CH₂)₄NH₂; and Hbenzyl (CH₂)₄NH₂;

-   -   wherein R²⁰ , R²¹, R²² and R²³ are as follows:

R²⁰ R²¹ R²² R²³ H benzyl isobutyl H; and methyl isobutyl methylisobutyl.

Exemplary Amino Acid units include, but are not limited to, units offormula VII where: R²⁰ is benzyl and R²¹ is —(CH₂)₄NH₂; R²⁰ is isopropyland R²¹ is —(CH₂)₄NH₂; or R²⁰ is isopropyl and R²¹ is —(CH₂)₃NHCONH₂.Another exemplary Amino Acid unit is a unit of formula VIII wherein R²⁰is benzyl, R²¹ is benzyl, and R²² is —(CH₂)₄NH₂.

Useful —W_(w)— units can be designed and optimized in their selectivityfor enzymatic cleavage by a particular enzyme, for example, atumor-associated protease. In one embodiment, a —W_(w)— unit is thatwhose cleavage is catalyzed by cathepsin B, C and D, or a plasminprotease.

In one embodiment, —W_(w)— is a dipeptide, tripeptide, tetrapeptide orpentapeptide. When R¹⁹, R²⁰, R²¹, R²² or R²³ is other than hydrogen, thecarbon atom to which R¹⁹, R²⁰, R²¹, R²² or R²³ is attached is chiral.

Each carbon atom to which R¹⁹, R²⁰, R²¹, R²² or R²³ is attached isindependently in the (S) or (R) configuration.

In one aspect of the Amino Acid unit, the Amino Acid unit isvaline-citrulline (vc or Val-Cit). In another aspect, the Amino Acidunit is phenylalanine-lysine (i.e., fk). In yet another aspect of theAmino Acid unit, the Amino Acid unit is N-methylvaline-citrulline. Inyet another aspect, the Amino Acid unit is 5-aminovaleric acid, homophenylalanine lysine, tetraisoquinolinecarboxylate lysine,cyclohexylalanine lysine, isonepecotic acid lysine, beta-alanine lysine,glycine serine valine glutamine and isonepecotic acid.

VIII.) The Spacer Unit

The Spacer unit (—Y—), when present, links an Amino Acid unit to theDrug unit when an Amino Acid unit is present. Alternately, the Spacerunit links the Stretcher unit to the Drug unit when the Amino Acid unitis absent. The Spacer unit also links the Drug unit to the Antibody unitwhen both the Amino Acid unit and Stretcher unit are absent.

Spacer units are of two general types: non self-immolative orself-immolative. A non self-immolative Spacer unit is one in which partor all of the Spacer unit remains bound to the Drug moiety aftercleavage, particularly enzymatic, of an Amino Acid unit from theantibody-drug conjugate. Examples of a non self-immolative Spacer unitinclude, but are not limited to a (glycine-glycine) Spacer unit and aglycine Spacer unit (both depicted in Scheme 1) (infra). When aconjugate containing a glycine-glycine Spacer unit or a glycine Spacerunit undergoes enzymatic cleavage via an enzyme (e.g., a tumor-cellassociated-protease, a cancer-cell-associated protease or alymphocyte-associated protease), a glycine-glycine-Drug moiety or aglycine-Drug moiety is cleaved from L-Aa-Ww-. In one embodiment, anindependent hydrolysis reaction takes place within the target cell,cleaving the glycine-Drug moiety bond and liberating the Drug.

In some embodiments, a non self-immolative Spacer unit (—Y—) is -Gly-.In some embodiments, a non self-immolative Spacer unit (—Y—) is-Gly-Gly-.

In one embodiment, a Drug-Linker conjugate is provided in which theSpacer unit is absent (—Y_(y)— where y=0), or a pharmaceuticallyacceptable salt or solvate thereof.

Alternatively, a conjugate containing a self-immolative Spacer unit canrelease -D. As used herein, the term “self-immolative Spacer” refers toa bifunctional chemical moiety that is capable of covalently linkingtogether two spaced chemical moieties into a stable tripartite molecule.It will spontaneously separate from the second chemical moiety if itsbond to the first moiety is cleaved.

In some embodiments, —Y_(y)— is a p-aminobenzyl alcohol (PAB) unit (seeSchemes 2 and 3) whose phenylene portion is substituted with Q_(m)wherein Q is —C₁-C₈ alkyl, —C₁-C₈ alkenyl, —C₁-C₈ alkynyl, —O—(C₁-C₈alkyl), —O—(C₁-C₈ alkenyl), —O—(C₁-C₈ alkynyl), -halogen, -nitro or-cyano; and m is an integer ranging from 0-4. The alkyl, alkenyl andalkynyl groups, whether alone or as part of another group, can beoptionally substituted.

In some embodiments, —Y— is a PAB group that is linked to —W_(w)— viathe amino nitrogen atom of the PAB group, and connected directly to -Dvia a carbonate, carbamate or ether group. Without being bound by anyparticular theory or mechanism, Scheme 2 depicts a possible mechanism ofDrug release of a PAB group which is attached directly to -D via acarbamate or carbonate group as described by Toki et al., 2002, J. Org.Chem. 67:1866-1872.

In Scheme 2, Q is —C₁-C₈ alkyl, —C₁-C₈ alkenyl, —C₁-C₈ alkynyl,—O—(C₁-C₈ alkyl), —O—(C₁-C₈ alkenyl), —O—(C₁-C₈ alkynyl), -halogen,-nitro or -cyano; m is an integer ranging from 0-4; and p ranges from 1to about 20. The alkyl, alkenyl and alkynyl groups, whether alone or aspart of another group, can be optionally substituted.

Without being bound by any particular theory or mechanism, Scheme 3depicts a possible mechanism of Drug release of a PAB group which isattached directly to -D via an ether or amine linkage, wherein Dincludes the oxygen or nitrogen group that is part of the Drug unit.

In Scheme 3, Q is —C₁-C₈ alkyl, —C₁-C₈ alkenyl, —C₁-C₈ alkynyl,—O—(C₁-C₈ alkyl), —O—(C₁-C₈ alkenyl), —O—(C₁-C₈ alkynyl), -halogen,-nitro or -cyano; m is an integer ranging from 0-4; and p ranges from 1to about 20. The alkyl, alkenyl and alkynyl groups, whether alone or aspart of another group, can be optionally substituted.

Other examples of self-immolative spacers include, but are not limitedto, aromatic compounds that are electronically similar to the PAB groupsuch as 2-aminoimidazol-5-methanol derivatives (Hay et al., 1999,Bioorg. Med. Chem. Lett. 9:2237) and ortho or para-aminobenzylacetals.Spacers can be used that undergo cyclization upon amide bond hydrolysis,such as substituted and unsubstituted 4-aminobutyric acid amides(Rodrigues et al., 1995, Chemistry Biology 2:223), appropriatelysubstituted bicyclo[2.2.1] and bicyclo[2.2.2] ring systems (Storm etal., 1972, J. Amer. Chem. Soc. 94:5815) and 2-aminophenylpropionic acidamides (Amsberry et al., 1990, J. Org. Chem. 55:5867). Elimination ofamine-containing drugs that are substituted at the a-position of glycine(Kingsbury et al., 1984, J. Med. Chem. 27:1447) are also examples ofself-immolative spacers.

In one embodiment, the Spacer unit is a branchedbis(hydroxymethyl)-styrene (BHMS) unit as depicted in Scheme 4, whichcan be used to incorporate and release multiple drugs.

In Scheme 4, Q is —C₁-C₈ alkyl, —C₁-C₈ alkenyl, —C₁-C₈ alkynyl,—O—(C₁-C₈ alkyl), —O—(C₁-C₈ alkenyl), —O—(C₁-C₈ alkynyl), -halogen,-nitro or -cyano; m is an integer ranging from 0-4; n is 0 or 1; and pranges raging from 1 to about 20. The alkyl, alkenyl and alkynyl groups,whether alone or as part of another group, can be optionallysubstituted.

In some embodiments, the -D moieties are the same. In yet anotherembodiment, the -D moieties are different.

In one aspect, Spacer units (—Y_(y)—) are represented by Formulas(X)-(XII):

-   -   wherein Q is —C₁-C₈ alkyl, —C₁-C₈ alkenyl, —C₁-C₈ alkynyl,        —O—(C₁-C₈ alkyl), —O—(C₁-C₈ alkenyl), —O—(C₁-C₈ alkynyl),        -halogen, -nitro or -cyano; and m is an integer ranging from        0-4. The alkyl, alkenyl and alkynyl groups, whether alone or as        part of another group, can be optionally substituted.

Embodiments of the Formula I and II comprising antibody-drug conjugatecompounds can include:

-   -   wherein w and y are each 0, 1 or 2, and,

-   -   wherein w and y are each 0,

IX.) The Drug Unit

The Drug moiety (D) can be any cytotoxic, cytostatic or immunomodulatory(e.g., immunosuppressive) drug. D is a Drug unit (moiety) having an atomthat can form a bond with the Spacer unit, with the Amino Acid unit,with the Stretcher unit or with the Antibody unit. In some embodiments,the Drug unit D has a nitrogen atom that can form a bond with the Spacerunit. As used herein, the terms “Drug unit” and “Drug moiety” aresynonymous and used interchangeably.

Useful classes of cytotoxic, cytostatic, or immunomodulatory agentsinclude, for example, antitubulin agents, DNA minor groove binders, DNAreplication inhibitors, and alkylating agents.

In some embodiments, the Drug is an auristatin, such as auristatin E(also known in the art as a derivative of dolastatin-10) or a derivativethereof. The auristatin can be, for example, an ester formed betweenauristatin E and a keto acid. For example, auristatin E can be reactedwith paraacetyl benzoic acid or benzoylvaleric acid to produce AEB andAEVB, respectively. Other typical auristatins include AFP, MMAF, andMMAE. The synthesis and structure of exemplary auristatins are describedin U.S. Patent Application Publication No. 2003-0083263; InternationalPatent Publication No. WO 04/010957, International Patent PublicationNo. WO 02/088172, and U.S. Pat. Nos. 7, 498,298, 6,884,869, 6,323,315;6,239,104; 6,034,065; 5,780,588; 5,665,860; 5,663,149; 5,635,483;5,599,902; 5,554,725; 5,530,097; 5,521,284; 5,504,191; 5,410,024;5,138,036; 5,076,973; 4,986,988; 4,978,744; 4,879,278; 4,816,444; and4,486,414, each of which is incorporated by reference herein in itsentirety and for all purposes.

Auristatins have been shown to interfere with microtubule dynamics andnuclear and cellular division and have anticancer activity. Auristatinsbind tubulin and can exert a cytotoxic or cytostatic effect on a191P4D12-expressing cell. There are a number of different assays, knownin the art, which can be used for determining whether an auristatin orresultant antibody-drug conjugate exerts a cytostatic or cytotoxiceffect on a desired cell line.

Methods for determining whether a compound binds tubulin are known inthe art. See, for example, Muller et al., Anal. Chem 2006, 78,4390-4397; Hamel et al., Molecular Pharmacology, 1995 47: 965-976; andHamel et al., The Journal of Biological Chemistry, 1990 265:28,17141-17149. For purposes of the present invention, the relativeaffinity of a compound to tubulin can be determined. Some preferredauristatins of the present invention bind tubulin with an affinityranging from 10 fold lower (weaker affinity) than the binding affinityof MMAE to tubulin to 10 fold, 20 fold or even 100 fold higher (higheraffinity) than the binding affinity of MMAE to tublin.

In some embodiments, -D is an auristatin of the formula D_(E) or D_(F):

-   -   or a pharmaceutically acceptable salt or solvate form thereof;    -   wherein, independently at each location:    -   the wavy line indicates a bond;    -   R² is —C₁-C₂₀ alkyl, —C₂-C₂₀ alkenyl, or —C₂-C₂₀ alkynyl;    -   R³ is —H, —C₁-C₂₀ alkyl, —C₂-C₂₀ alkenyl, —C₂-C₂₀ alkynyl,        -carbocycle, —C₁-C₂₀ alkylene(carbocycle), —C₂-C₂₀        alkenylene(carbocycle), —C₂-C₂₀ alkynylene(carbocycle), -aryl,        —C₁-C₂₀ alkylene(aryl), —C₂-C₂₀ alkenylene(aryl), —C₂-C₂₀        alkynylene(aryl), heterocycle, —C₁-C₂₀ alkylene(heterocycle),        —C₂-C₂₀ alkenylene(heterocycle), or —C₂-C₂₀        alkynylene(heterocycle);    -   R⁴ is —H, —C₁-C₂₀ alkyl, —C₂-C₂₀ alkenyl, —C₂-C₂₀ alkynyl,        carbocycle, —C₁-C₂₀ alkylene (carbocycle), —C₂-C₂₀        alkenylene(carbocycle), —C₂-C₂₀ alkynylene(carbocycle), aryl,        —C₁-C₂₀ alkylene(aryl), —C₂-C₂₀ alkenylene(aryl), —C₂-C₂₀        alkynylene(aryl), -heterocycle, —C₁-C₂₀ alkylene(heterocycle),        —C₂-C₂₀ alkenylene(heterocycle), or —C₂-C₂₀        alkynylene(heterocycle);    -   R⁵ is —H or —C₁-C₈ alkyl;    -   or R⁴ and R⁵ jointly form a carbocyclic ring and have the        formula —(CR^(a)R^(b))_(s)— wherein R^(a) and R^(b) are        independently —H, —C₁-C₂₀ alkyl, —C₂-C₂₀ alkenyl, —C₂-C₂₀        alkynyl, or -carbocycle and s is 2, 3, 4, 5 or 6,    -   R⁶ is —H, —C₁-C₂₀ alkyl, —C₂-C₂₀ alkenyl, or —C₂-C₂₀ alkynyl;    -   R⁷ is —H, —C₁-C₂₀ alkyl, —C₂-C₂₀ alkenyl, —C₂-C₂₀ alkynyl,        carbocycle, —C₁-C₂₀ alkylene(carbocycle), —C₂-C₂₀        alkenylene(carbocycle), —C₂-C₂₀ alkynylene(carbocycle), -aryl,        —C₁-C₂₀ alkylene(aryl), —C₂-C₂₀ alkenylene(aryl), —C₂-C₂₀        alkynylene(aryl), heterocycle, —C₁-C₂₀ alkylene(heterocycle),        —C₂-C₂₀ alkenylene(heterocycle), or —C₂-C₂₀        alkynylene(heterocycle);    -   each R⁸ is independently —H, —OH, —C₁-C₂₀ alkyl, —C₂-C₂₀        alkenyl, —C₂-C₂₀ alkynyl, —O—(C₁-C₂₀ alkyl), —O—(C₂-C₂₀        alkenyl), —O—(C₁-C₂₀ alkynyl), or -carbocycle;    -   R⁹ is —H, —C₁-C₂₀ alkyl, —C₂-C₂₀ alkenyl, or —C₂-C₂₀ alkynyl;    -   R²⁴ is -aryl, -heterocycle, or -carbocycle;    -   R²⁵ is —H, C₁-C₂₀ alkyl, —C₂-C₂₀ alkenyl, —C₂-C₂₀ alkynyl,        -carbocycle, —O—(C₁-C₂₀ alkyl), —O—(C₂-C₂₀ alkenyl), —O—(C₂-C₂₀        alkynyl), or OR¹⁸ wherein R¹⁸ is —H, a hydroxyl protecting        group, or a direct bond where OR¹⁸ represents ═O;    -   R²⁶ is —H, —C₁-C₂₀ alkyl, —C₂-C₂₀ alkenyl, or —C₂-C₂₀ alkynyl,        -aryl, -heterocycle, or -carbocycle;    -   R¹⁰ is -aryl or -heterocycle;    -   Z is —O, —S, —NH, or —NR¹², wherein R¹² is —C₁-C₂₀ alkyl,        —C₂-C₂₀ alkenyl, or —C₂-C₂₀ alkynyl;    -   R¹¹ is —H, —C₁-C₂₀ alkyl, —C₂-C₂₀ alkenyl, —C₂-C₂₀ alkynyl,        -aryl, -heterocycle, —(R¹³O)_(m)—R¹⁴, —(R¹³O)_(m)—CH(R¹⁵)₂;    -   m is an integer ranging from 1-1000 or m=0-1000;    -   R¹³ is —C₂-C₂₀ alkylene, —C₂-C₂₀ alkenylene, or —C₂-C₂₀        alkynylene;    -   R¹⁴ is —H, —C₁-C₂₀ alkyl, —C₂-C₂₀ alkenyl, or —C₂-C₂₀ alkynyl;    -   each occurrence of R¹⁵ is independently —H, —COOH,        —(CH₂)_(n)—N(R¹⁶)₂, —(CH₂)_(n)—SO₃H, —(CH₂)_(n)—SO₃—C₁-C₂₀        alkyl, —(CH₂)_(n)—SO₃—C₂-C₂₀ alkenyl, or —(CH₂)_(n)—SO₃—C₂-C₂₀        alkynyl;    -   each occurrence of R¹⁶ is independently —H, —C₁-C₂₀ alkyl,        —C₂-C₂₀ alkenyl, —C₂-C₂₀ alkynyl or —(CH₂)_(n)—COOH; and    -   n is an integer ranging from 0 to 6;    -   wherein said alkyl, alkenyl, alkynyl, alkylene, alkenylene,        alkynyklene, aryl, carbocyle, and heterocycle radicals, whether        alone or as part of another group, are optionally substituted.

Auristatins of the formula D_(E) include those wherein said alkyl,alkenyl, alkynyl, alkylene, alkenylene, alkynyklene, aryl, carbocyle,and heterocycle radicals are unsubstituted.

Auristatins of the formula D_(E) include those wherein the groups of R²,R³, R⁴, R⁵, R⁶, R⁷, R⁸, and R⁹ are unsubstituted and the groups of R¹⁹,R²⁰ and R²¹ are optionally substituted as described herein.

Auristatins of the formula D_(E) include those wherein

-   -   R² is C₁-C₈ alkyl;    -   R³, R⁴ and R⁷ are independently selected from —H, —C₁-C₂₀ alkyl,        —C₂-C₂₀ alkenyl, —C₂-C₂₀ alkynyl, monocyclic C₃-C₆ carbocycle,        —C₁-C₂₀ alkylene(monocyclic C₃-C₆ carbocycle), —C₂-C₂₀        alkenylene(monocyclic C₃-C₆ carbocycle), —C₂-C₂₀        alkynylene(monocyclic C₃-C₆ carbocycle), C₆-C₁₀ aryl, —C₁-C₂₀        alkylene(C₆-C₁₀ aryl), —C₂-C₂₀ alkenylene(C₆-C₁₀ aryl), —C₂-C₂₀        alkynylene(C₆-C₁₀ aryl), heterocycle, —C₁-C₂₀        alkylene(heterocycle), —C₂-C₂₀ alkenylene(heterocycle), or        —C₂-C₂₀ alkynylene(heterocycle); wherein said alkyl, alkenyl,        alkynyl, alkylene, alkenylene, alkynylene, carbocycle, aryl and        heterocycle radicals are optionally substituted;    -   R⁵ is —H;    -   R⁶ is —C₁-C₈ alkyl;    -   each R⁸ is independently selected from —OH, —O—(C₁-C₂₀ alkyl),        —O—(C₂-C₂₀ alkenyl), or —O—(C₂-C₂₀ alkynyl) wherein said alkyl,        alkenyl, and alkynyl radicals are optionally substituted;    -   R⁹ is —H or —C₁-C₈ alkyl;    -   R²⁴ is optionally substituted -phenyl;    -   R²⁵ is —OR¹⁸; wherein R¹⁸ is H, a hydroxyl protecting group, or        a direct bond where OR¹⁸ represents ═O;    -   R²⁶ is selected from —H, —C₁-C₂₀ alkyl, —C₂-C₂₀ alkenyl, —C₂-C₂₀        alkynyl, or -carbocycle; wherein said alkyl, alkenyl, alkynyl        and carbocycle radicals are optionally substituted; or a        pharmaceutically acceptable salt or solvate form thereof.

Auristatins of the formula D_(E) include those wherein

-   -   R² is methyl;    -   R³ is —H, —C₁-C₈ alkyl, —C₂-C₈ alkenyl, or C₂-C₈ alkynyl,        wherein said alkyl, alkenyl and alkynyl radicals are optionally        substituted;    -   R⁴ is —H, —C₁-C₈ alkyl, —C₂-C₈ alkenyl, —C₂-C₈ alkynyl,        monocyclic C₃-C₆ carbocycle, —C₆-C₁₀ aryl, —C₁-C₈        alkylene(C₆-C₁₀ aryl), —C₂-C₈ alkenylene(C₆-C₁₀ aryl), —C₂-C₈        alkynylene(C₆-C₁₀ aryl), —C₁-C₈ alkylene(monocyclic C₃-C₆        carbocycle), —C₂-C₈ alkenylene(monocyclic C₃-C₆ carbocycle),        —C₂-C₈ alkynylene(monocyclic C₃-C₆ carbocycle); wherein said        alkyl, alkenyl, alkynyl, alkylene, alkenylene, alkynylene, aryl        and carbocycle radicals whether alone or as part of another        group are optionally substituted;    -   R⁵ is —H;    -   R⁶ is methyl;    -   R⁷ is —C₁-C₈ alkyl, —C₂-C₈ alkenyl or —C₂-C₈ alkynyl;    -   each R⁸ is methoxy;    -   R⁹ is —H or —C₁-C₈ alkyl;    -   R²⁴ is -phenyl;    -   R²⁵ is —OR¹⁸; wherein R¹⁸ is H, a hydroxyl protecting group, or        a direct bond where OR¹⁸ represents ═O;    -   R²⁶ is methyl;    -   or a pharmaceutically acceptable salt form thereof.

Auristatins of the formula D_(E) include those wherein:

-   -   R² is methyl; R³ is —H or —C₁-C₃ alkyl; R⁴ is —C₁-C₅ alkyl; R⁵        is —H; R⁶ is methyl; R⁷ is isopropyl or sec-butyl; R⁸ is        methoxy; R⁹ is —H or —C₁-C₈ alkyl; R²⁴ is phenyl; R²⁵ is —OR¹⁸;        wherein R¹⁸ is —H, a hydroxyl protecting group, or a direct bond        where OR¹⁸ represents ═O; and R²⁶ is methyl; or a        pharmaceutically acceptable salt or solvate form thereof.

Auristatins of the formula D_(E) include those wherein:

-   -   R² is methyl or C₁-C₃ alkyl,    -   R³ is —H or —C₁-C₃ alkyl;    -   R⁴ is —C₁-C₅ alkyl;    -   R⁵ is H;    -   R⁶ is C1-C3 alkyl;    -   R⁷ is —C₁-C₅ alkyl;    -   R⁸ is —C₁-C₃ alkoxy;    -   R⁹ is —H or —C₁-C₈ alkyl;    -   R²⁴ is phenyl;    -   R²⁵ is —OR¹⁸; wherein R¹⁸ is —H, a hydroxyl protecting group, or        a direct bond where OR¹⁸ represents ═O; and    -   R²⁶ is —C₁-C₃ alkyl;    -   or a pharmaceutically acceptable salt form thereof.

Auristatins of the formula D_(F) include those wherein

-   -   R² is methyl;    -   R³, R⁴, and R⁷ are independently selected from —H, —C₁-C₂₀        alkyl, -C₂-C₂₀ alkenyl, —C₂-C₂₀ alkynyl, monocyclic C₃-C₆        carbocycle, —C₁-C₂₀ alkylene(monocyclic C₃-C₆ carbocycle),        —C₂-C₂₀ alkenylene(monocyclic C₃-C₆ carbocycle), —C₂-C₂₀        alkynylene(monocyclic C₃-C₆ carbocycle), —C₆-C₁₀ aryl, —C₁-C₂₀        alkylene(C₆-C₁₀ aryl), —C₂-C₂₀ alkenylene(C₆-C₁₀ aryl), —C₂-C₂₀        alkynylene(C₆-C₁₀ aryl), heterocycle, —C₁-C₂₀        alkylene(heterocycle), —C₂-C₂₀ alkenylene(heterocycle), or        —C₂-C₂₀ alkynylene(heterocycle); wherein said alkyl, alkenyl,        alkynyl, alkylene, alkenylene, alkynylene, carbocycle, aryl and        heterocycle radicals whether alone or as part of another group        are optionally substituted;    -   R⁵ is —H;    -   R⁶ is methyl;    -   each R⁸ is methoxy;    -   R⁹ is —H, —C₁-C₂₀ alkyl, —C₂-C₂₀ alkenyl, or —C₂-C₂₀ alkynyl;        wherein said alkyl, alkenyl and alkynyl radical are optionally        substituted;    -   R¹⁰ is optionally substituted aryl or optionally substituted        heterocycle;    -   Z is —O—, —S—, —NH—, or —NR¹², wherein R¹² is —C₁-C₂₀ alkyl,        —C₂-C₂₀ alkenyl, or —C₂-C₂₀ alkynyl, each of which is optionally        substituted;    -   R¹¹ is —H, —C₁-C₂₀ alkyl, —C₂-C₂₀ alkenyl, —C₂-C₂₀ alkynyl,        -aryl, -heterocycle, —(R¹³O)_(m)—R¹⁴, or —(R¹³O)_(m)—CH(R¹⁵)₂,        wherein said alkyl, alkenyl, alkynyl, aryl and heterocycle        radicals are optionally substituted;    -   m is an integer ranging from 1-1000 or m=0;    -   R¹³ is —C₂-C₂₀ alkylene, —C₂-C₂₀ alkenylene, or —C₂-C₂₀        alkynylene, each of which is optionally substituted;    -   R¹⁴ is —H, —C₁-C₂₀ alkyl, —C₂-C₂₀ alkenyl, or —C₂-C₂₀ alkynyl        wherein said alkyl, alkenyl and alkynyl radicals are optionally        substituted;    -   each occurrence of R¹⁵ is independently —H, —COOH,        —(CH₂)_(n)—N(R¹⁶)₂, —(CH₂)_(n)—SO₃H, —(CH₂)_(n)—SO₃—C₁-C₂₀        alkyl, —(CH₂)_(n)—SO₃—C₂-C₂₀ alkenyl, or —(CH₂)_(n)—SO₃—C₂-C₂₀        alkynyl wherein said alkyl, alkenyl and alkynyl radicals are        optionally substituted;    -   each occurrence of R¹⁶ is independently —H, —C₁-C₂₀ alkyl,        —C₂-C₂₀ alkenyl, —C₂-C₂₀ alkynyl or —(CH₂)_(n)—COOH wherein said        alkyl, alkenyl and alkynyl radicals are optionally substituted;    -   n is an integer ranging from 0 to 6;    -   or a pharmaceutically acceptable salt thereof.

In certain of these embodiments, R¹⁰ is optionally substituted phenyl.

Auristatins of the formula D_(F) include those wherein the groups of R²,R³, R⁴, R⁵, R⁶, R⁷, R⁸, and R⁹ are unsubstituted and the groups of R¹⁰and R¹¹ are as described herein.

Auristatins of the formula D_(F) include those wherein said alkyl,alkenyl, alkynyl, alkylene, alkenylene, alkynyklene, aryl, carbocyle,and heterocycle radicals are unsubstituted

Auristatins of the formula D_(F) include those wherein

-   -   R² is —C₁-C₃ alkyl; R³ is —H or —C₁-C₃ alkyl; R⁴ is —C₁-C₅        alkyl; R⁵ is —H; R⁶ is —C₁-C₃ alkyl; R⁷ is —C₁-C₅ alkyl; R⁸ is        —C₁-C₃ alkoxy; R⁹ is —H or —C₁-C₈ alkyl; R¹⁰ is optionally        substituted phenyl; Z is —O—, —S—, or —NH—; R¹¹ is as defined        herein; or a pharmaceutically acceptable salt thereof.

Auristatins of the formula D_(F) include those wherein

-   -   R² is methyl; R³ is —H or —C₁-C₃ alkyl; R⁴ is —C₁-C₅ alkyl; R⁵        is —H; R⁶ is methyl; R⁷ is isopropyl or sec-butyl; R⁸ is        methoxy; R⁹ is —H or —C₁-C₈ alkyl; R¹⁰ is optionally substituted        phenyl; Z is —O—, —S—, or —NH—; and R¹¹ is as defined herein; or        a pharmaceutically acceptable salt thereof.

Auristatins of the formula D_(F) include those wherein

-   -   R² is methyl; R³ is —H or —C₁-C₃ alkyl; R⁴ is —C₁-C₅ alkyl; R⁵        is —H; R⁶ is methyl; R⁷ is isopropyl or sec-butyl; R⁸ is        methoxy; R⁹ is —H or C₁-C₈ alkyl; R¹⁰ is phenyl; and Z is —O— or        —NH— and R¹¹ is as defined herein, preferably hydrogen; or a        pharmaceutically acceptable salt form thereof.

Auristatins of the formula D_(F) include those wherein

-   -   R² is —C₁-C₃ alkyl; R³ is —H or —C₁-C₃ alkyl; R⁴ is —C₁-C₅        alkyl; R⁵ is —H; R⁶ is —C₁-C₃ alkyl; R⁷ is —C₁-C₅ alkyl; R⁸ is        —C₁-C₃ alkoxy; R⁹ is —H or —C₁-C₈ alkyl; R¹⁰ is phenyl; and Z is        —O— or —NH— and R¹¹ is as defined herein, preferably hydrogen;        or a pharmaceutically acceptable salt form thereof.

Auristatins of the formula D_(E) or D_(F) include those wherein R³, R⁴and R⁷ are independently isopropyl or sec-butyl and R⁵ is —H. In anexemplary embodiment, R³ and R⁴ are each isopropyl, R⁵ is H, and R⁷ issec-butyl. The remainder of the substituents are as defined herein.

Auristatins of the formula D_(E) or D_(F) include those wherein R² andR⁶ are each methyl, and R⁹ is H. The remainder of the substituents areas defined herein.

Auristatins of the formula D_(E) or D_(F) include those wherein eachoccurrence of R⁸ is —OCH₃. The remainder of the substituents are asdefined herein.

Auristatins of the formula D_(E) or D_(F) include those wherein R³ andR⁴ are each isopropyl, R² and R⁶ are each methyl, R⁵ is H, R⁷ issec-butyl, each occurrence of R⁸ is —OCH₃, and R⁹ is H. The remainder ofthe substituents are as defined herein.

Auristatins of the formula D_(F) include those wherein Z is —O— or —NH—.The remainder of the substituents are as defined herein.

Auristatins of the formula D_(F) include those wherein R¹⁰ is aryl. Theremainder of the substituents are as defined herein.

Auristatins of the formula D_(F) include those wherein R¹⁰ is -phenyl.The remainder of the substituents are as defined herein.

Auristatins of the formula D_(F) include those wherein Z is —O—, and R¹¹is H, methyl or t-butyl. The remainder of the substituents are asdefined herein.

Auristatins of the formula D_(F) include those wherein, when Z is —NH—,R¹¹ is —(R¹³O)_(m)—CH(R¹⁵)₂, wherein R¹⁵ is —(CH₂)_(n)—N(R¹⁶)₂, and R¹⁶is —C₁-C₈ alkyl or —(CH₂)_(n)—COOH. The remainder of the substituentsare as defined herein.

Auristatins of the formula D_(F) include those wherein when Z is —NH—,R¹¹ is —(R¹³O)_(m)—CH(R¹⁵)₂, wherein R¹⁵ is —(CH₂)_(n)—SO₃H. Theremainder of the substituents are as defined herein.

In preferred embodiments, when D is an auristatin of formula D_(E), w isan integer ranging from 1 to 12, preferably 2 to 12, y is 1 or 2, and ais preferably 1.

In some embodiments, wherein D is an auristatin of formula D_(F), a is 1and w and y are 0.

Illustrative Drug units (-D) include the drug units having the followingstructures:

-   -   or pharmaceutically acceptable salts or solvates thereof.

In one aspect, hydrophilic groups, such as but not limited totriethylene glycol esters (TEG) can be attached to the Drug Unit at R¹¹.Without being bound by theory, the hydrophilic groups assist in theinternalization and non-agglomeration of the Drug Unit.

In some embodiments, the Drug unit is not TZT-1027. In some embodiments,the Drug unit is not auristatin E, dolastatin 10, or auristatin PE.

Exemplary antibody-drug conjugate compounds have the followingstructures wherein “L” or “mAb-s-” represents an 191P4D12 MAb designatedHa22-2(2,4)6.1 set forth herein:

-   -   or pharmaceutically acceptable salt thereof.

In some embodiments, the Drug Unit is a calicheamicin, camptothecin, amaytansinoid, or an anthracycline. In some embodiments the drug is ataxane, a topoisomerase inhibitor, a vinca alkaloid, or the like.

In some typical embodiments, suitable cytotoxic agents include, forexample, DNA minor groove binders (e.g., enediynes and lexitropsins, aCBI compound; see also U.S. Pat. No. 6,130,237), duocarmycins, taxanes(e.g., paclitaxel and docetaxel), puromycins, and vinca alkaloids. Othercytotoxic agents include, for example, CC-1065, SN-38, topotecan,morpholino-doxorubicin, rhizoxin, cyanomorpholino-doxorubicin,echinomycin, combretastatin, netropsin, epothilone A and B,estramustine, cryptophysins, cemadotin, maytansinoids, discodermolide,eleutherobin, and mitoxantrone.

In some embodiments, the Drug is an anti-tubulin agent. Examples ofanti-tubulin agents include, auristatins, taxanes (e.g., Taxol®(paclitaxel), Taxotere® (docetaxel)), T67 (Tularik) and vinca alkyloids(e.g., vincristine, vinblastine, vindesine, and vinorelbine). Otherantitubulin agents include, for example, baccatin derivatives, taxaneanalogs (e.g., epothilone A and B), nocodazole, colchicine and colcimid,estramustine, cryptophycins, cemadotin, maytansinoids, combretastatins,discodermolide, and eleutherobin.

In certain embodiments, the cytotoxic agent is a maytansinoid, anothergroup of anti-tubulin agents. For example, in specific embodiments, themaytansinoid is maytansine or DM-1 (ImmunoGen, Inc.; see also Chari etal., 1992, Cancer Res. 52:127-131).

In certain embodiments, the cytotoxic or cytostatic agent is adolastatin. In certain embodiments, the cytotoxic or cytostatic agent isof the auristatin class. Thus, in a specific embodiment, the cytotoxicor cytostatic agent is MMAE (Formula XI). In another specificembodiment, the cytotoxic or cytostatic agent is AFP (Formula XVI).

In certain embodiments, the cytotoxic or cytostatic agent is a compoundof formulas XII-XXI or pharmaceutically acceptable salt thereof:

X.) Drug Loading

Drug loading is represented by p and is the average number of Drugmoieties per antibody in a molecule. Drug loading may range from 1 to 20drug moieties (D) per antibody. ADCs of the invention includecollections of antibodies conjugated with a range of drug moieties, from1 to 20. The average number of drug moieties per antibody inpreparations of ADC from conjugation reactions may be characterized byconventional means such as mass spectroscopy and, ELISA assay. Thequantitative distribution of ADC in terms of p may also be determined.In some instances, separation, purification, and characterization ofhomogeneous ADC where p is a certain value from ADC with other drugloadings may be achieved by means such as electrophoresis.

For some antibody-drug conjugates, p may be limited by the number ofattachment sites on the antibody. For example, where the attachment is acysteine thiol, as in the exemplary embodiments above, an antibody mayhave only one or several cysteine thiol groups, or may have only one orseveral sufficiently reactive thiol groups through which a linker may beattached. In certain embodiments, higher drug loading, e.g. p>5, maycause aggregation, insolubility, toxicity, or loss of cellularpermeability of certain antibody-drug conjugates. In certainembodiments, the drug loading for an ADC of the invention ranges from 1to about 8; from about 2 to about 6; from about 3 to about 5; from about3 to about 4; from about 3.1 to about 3.9; from about 3.2 to about 3.8;from about 3.2 to about 3.7; from about 3.2 to about 3.6; from about 3.3to about 3.8; or from about 3.3 to about 3.7. Indeed, it has been shownthat for certain ADCs, the optimal ratio of drug moieties per antibodymay be less than 8, and may be about 2 to about 5. See U.S. Pat. No.7,498,298 (herein incorporated by reference in its entirety).

In certain embodiments, fewer than the theoretical maximum of drugmoieties are conjugated to an antibody during a conjugation reaction. Anantibody may contain, for example, lysine residues that do not reactwith the drug-linker intermediate or linker reagent, as discussed below.Generally, antibodies do not contain many free and reactive cysteinethiol groups which may be linked to a drug moiety; indeed most cysteinethiol residues in antibodies exist as disulfide bridges. In certainembodiments, an antibody may be reduced with a reducing agent such asdithiothreitol (DTT) or tricarbonylethylphosphine (TCEP), under partialor total reducing conditions, to generate reactive cysteine thiolgroups. In certain embodiments, an antibody is subjected to denaturingconditions to reveal reactive nucleophilic groups such as lysine orcysteine.

The loading (drug/antibody ratio) of an ADC may be controlled indifferent ways, e.g., by: (i) limiting the molar excess of drug-linkerintermediate or linker reagent relative to antibody, (ii) limiting theconjugation reaction time or temperature, (iii) partial or limitingreductive conditions for cysteine thiol modification, (iv) engineeringby recombinant techniques the amino acid sequence of the antibody suchthat the number and position of cysteine residues is modified forcontrol of the number and/or position of linker-drug attachments (suchas thioMab or thioFab prepared as disclosed herein and in WO2006/034488(herein incorporated by reference in its entirety)).

It is to be understood that where more than one nucleophilic groupreacts with a drug-linker intermediate or linker reagent followed bydrug moiety reagent, then the resulting product is a mixture of ADCcompounds with a distribution of one or more drug moieties attached toan antibody. The average number of drugs per antibody may be calculatedfrom the mixture by a dual ELISA antibody assay, which is specific forantibody and specific for the drug. Individual ADC molecules may beidentified in the mixture by mass spectroscopy and separated by HPLC,e.g. hydrophobic interaction chromatography (see, e.g., Hamblett, K. J.,et al. “Effect of drug loading on the pharmacology, pharmacokinetics,and toxicity of an anti-CD30 antibody-drug conjugate,” Abstract No. 624,American Association for Cancer Research, 2004 Annual Meeting, Mar.27-31, 2004, Proceedings of the AACR, Volume 45, March 2004; Alley, S.C., et al. “Controlling the location of drug attachment in antibody-drugconjugates,” Abstract No. 627, American Association for Cancer Research,2004 Annual Meeting, Mar. 27-31, 2004, Proceedings of the AACR, Volume45, March 2004). In certain embodiments, a homogeneous ADC with a singleloading value may be isolated from the conjugation mixture byelectrophoresis or chromatography.

XI.) Methods of Determining Cytotoxic Effect of ADCs

Methods of determining whether a Drug or Antibody-Drug conjugate exertsa cytostatic and/or cytotoxic effect on a cell are known. Generally, thecytotoxic or cytostatic activity of an Antibody Drug conjugate can bemeasured by: exposing mammalian cells expressing a target protein of theAntibody Drug conjugate in a cell culture medium; culturing the cellsfor a period from about 6 hours to about 5 days; and measuring cellviability. Cell-based in vitro assays can be used to measure viability(proliferation), cytotoxicity, and induction of apoptosis (caspaseactivation) of the Antibody Drug conjugate.

For determining whether an Antibody Drug conjugate exerts a cytostaticeffect, a thymidine incorporation assay may be used. For example, cancercells expressing a target antigen at a density of 5,000 cells/well of a96-well plated can be cultured for a 72-hour period and exposed to 0.5μCi of ³H-thymidine during the final 8 hours of the 72-hour period. Theincorporation of ³H-thymidine into cells of the culture is measured inthe presence and absence of the Antibody Drug conjugate.

For determining cytotoxicity, necrosis or apoptosis (programmed celldeath) can be measured. Necrosis is typically accompanied by increasedpermeability of the plasma membrane; swelling of the cell, and ruptureof the plasma membrane. Apoptosis is typically characterized by membraneblebbing, condensation of cytoplasm, and the activation of endogenousendonucleases. Determination of any of these effects on cancer cellsindicates that an Antibody Drug conjugate is useful in the treatment ofcancers.

Cell viability can be measured by determining in a cell the uptake of adye such as neutral red, trypan blue, or ALAMAR™ blue (see, e.g., Pageet al., 1993, Intl. J. Oncology 3:473-476). In such an assay, the cellsare incubated in media containing the dye, the cells are washed, and theremaining dye, reflecting cellular uptake of the dye, is measuredspectrophotometrically. The protein-binding dye sulforhodamine B (SRB)can also be used to measure cytoxicity (Skehan et al., 1990, J. Natl.Cancer Inst. 82:1107-12).

Alternatively, a tetrazolium salt, such as MTT, is used in aquantitative colorimetric assay for mammalian cell survival andproliferation by detecting living, but not dead, cells (see, e.g.,Mosmann, 1983, J. Immunol. Methods 65:55-63).

Apoptosis can be quantitated by measuring, for example, DNAfragmentation. Commercial photometric methods for the quantitative invitro determination of DNA fragmentation are available. Examples of suchassays, including TUNEL (which detects incorporation of labelednucleotides in fragmented DNA) and ELISA-based assays, are described inBiochemica, 1999, no. 2, pp. 34-37 (Roche Molecular Biochemicals).

Apoptosis can also be determined by measuring morphological changes in acell. For example, as with necrosis, loss of plasma membrane integritycan be determined by measuring uptake of certain dyes (e.g., afluorescent dye such as, for example, acridine orange or ethidiumbromide). A method for measuring apoptotic cell number has beendescribed by Duke and Cohen, Current Protocols in Immunology (Coligan etal. eds., 1992, pp. 3.17.1-3.17.16). Cells also can be labeled with aDNA dye (e.g., acridine orange, ethidium bromide, or propidium iodide)and the cells observed for chromatin condensation and margination alongthe inner nuclear membrane. Other morphological changes that can bemeasured to determine apoptosis include, e.g., cytoplasmic condensation,increased membrane blebbing, and cellular shrinkage.

The presence of apoptotic cells can be measured in both the attached and“floating” compartments of the cultures. For example, both compartmentscan be collected by removing the supernatant, trypsinizing the attachedcells, combining the preparations following a centrifugation wash step(e.g., 10 minutes at 2000 rpm), and detecting apoptosis (e.g., bymeasuring DNA fragmentation). (See, e.g., Piazza et al., 1995, CancerResearch 55:3110-16).

In vivo, the effect of a 191P4D12 therapeutic composition can beevaluated in a suitable animal model. For example, xenogenic cancermodels can be used, wherein cancer explants or passaged xenografttissues are introduced into immune compromised animals, such as nude orSCID mice (Klein et al., 1997, Nature Medicine 3: 402-408). For example,PCT Patent Application WO98/16628 and U.S. Pat. No. 6,107,540 describevarious xenograft models of human prostate cancer capable ofrecapitulating the development of primary tumors, micrometastasis, andthe formation of osteoblastic metastases characteristic of late stagedisease. Efficacy can be predicted using assays that measure inhibitionof tumor formation, tumor regression or metastasis, and the like.

In vivo assays that evaluate the promotion of apoptosis are useful inevaluating therapeutic compositions. In one embodiment, xenografts fromtumor bearing mice treated with the therapeutic composition can beexamined for the presence of apoptotic foci and compared to untreatedcontrol xenograft-bearing mice. The extent to which apoptotic foci arefound in the tumors of the treated mice provides an indication of thetherapeutic efficacy of the composition.

The therapeutic compositions used in the practice of the foregoingmethods can be formulated into pharmaceutical compositions comprising acarrier suitable for the desired delivery method. Suitable carriersinclude any material that when combined with the therapeutic compositionretains the anti-tumor function of the therapeutic composition and isgenerally non-reactive with the patient's immune system. Examplesinclude, but are not limited to, any of a number of standardpharmaceutical carriers such as sterile phosphate buffered salinesolutions, bacteriostatic water, and the like (see, generally,Remington's Pharmaceutical Sciences 16th Edition, A. Osal., Ed., 1980).

Therapeutic formulations can be solubilized and administered via anyroute capable of delivering the therapeutic composition to the tumorsite. Potentially effective routes of administration include, but arenot limited to, intravenous, parenteral, intraperitoneal, intramuscular,intratumor, intradermal, intraorgan, orthotopic, and the like. Apreferred formulation for intravenous injection comprises thetherapeutic composition in a solution of preserved bacteriostatic water,sterile unpreserved water, and/or diluted in polyvinylchloride orpolyethylene bags containing 0.9% sterile Sodium Chloride for Injection,USP. Therapeutic protein preparations can be lyophilized and stored assterile powders, preferably under vacuum, and then reconstituted inbacteriostatic water (containing for example, benzyl alcoholpreservative) or in sterile water prior to injection.

Dosages and administration protocols for the treatment of cancers usingthe foregoing methods will vary with the method and the target cancer,and will generally depend on a number of other factors appreciated inthe art.

XII.) Treatment of Cancer(s) Expressing 191P4D12

The identification of 191P4D12 as a protein that is normally expressedin a restricted set of tissues, but which is also expressed in cancerssuch as those listed in Table I, opens a number of therapeuticapproaches to the treatment of such cancers.

Of note, targeted antitumor therapies have been useful even when thetargeted protein is expressed on normal tissues, even vital normal organtissues. A vital organ is one that is necessary to sustain life, such asthe heart or colon. A non-vital organ is one that can be removedwhereupon the individual is still able to survive. Examples of non-vitalorgans are ovary, breast, and prostate.

Expression of a target protein in normal tissue, even vital normaltissue, does not defeat the utility of a targeting agent for the proteinas a therapeutic for certain tumors in which the protein is alsooverexpressed. For example, expression in vital organs is not in and ofitself detrimental. In addition, organs regarded as dispensable, such asthe prostate and ovary, can be removed without affecting mortality.Finally, some vital organs are not affected by normal organ expressionbecause of an immunoprivilege. Immunoprivileged organs are organs thatare protected from blood by a blood-organ barrier and thus are notaccessible to immunotherapy. Examples of immunoprivileged organs are thebrain and testis.

Accordingly, therapeutic approaches that inhibit the activity of a191P4D12 protein are useful for patients suffering from a cancer thatexpresses 191P4D12. These therapeutic approaches generally fall intothree classes. The first class modulates 191P4D12 function as it relatesto tumor cell growth leading to inhibition or retardation of tumor cellgrowth or inducing its killing. The second class comprises variousmethods for inhibiting the binding or association of a 191P4D12 proteinwith its binding partner or with other proteins. The third classcomprises a variety of methods for inhibiting the transcription of a191P4D12 gene or translation of 191P4D12 mRNA.

Accordingly, cancer patients can be evaluated for the presence and levelof 191P4D12 expression, preferably using immunohistochemical assessmentsof tumor tissue, quantitative 191P4D12 imaging, or other techniques thatreliably indicate the presence and degree of 191P4D12 expressionImmunohistochemical analysis of tumor biopsies or surgical specimens ispreferred for this purpose. Methods for immunohistochemical analysis oftumor tissues are well known in the art.

XIII.) 191P4D12 as a Target for Antibody-Based Therapy

191P4D12 is an attractive target for antibody-based therapeuticstrategies. A number of antibody strategies are known in the art fortargeting both extracellular and intracellular molecules (see, e.g.,complement and ADCC mediated killing as well as the use of intrabodies).Because 191P4D12 is expressed by cancer cells of various lineagesrelative to corresponding normal cells, systemic administration of191P4D12-immunoreactive compositions are prepared that exhibit excellentsensitivity without toxic, non-specific and/or non-target effects causedby binding of the immunoreactive composition to non-target organs andtissues. Antibodies specifically reactive with domains of 191P4D12 areuseful to treat 191P4D12-expressing cancers systemically, preferably asantibody drug conjugates (i.e. ADCs) wherein the conjugate is with atoxin or therapeutic agent.

Those skilled in the art understand that antibodies can be used tospecifically target and bind immunogenic molecules such as animmunogenic region of a 191P4D12 sequence shown in FIG. 1. In addition,skilled artisans understand that it is routine to conjugate antibodiesto cytotoxic agents (see, e.g., Slevers et al. Blood 93:11 3678-3684(Jun. 1, 1999)). When cytotoxic and/or therapeutic agents are delivereddirectly to cells, such as by conjugating them to antibodies specificfor a molecule expressed by that cell (e.g. 191P4D12), the cytotoxicagent will exert its known biological effect (i.e. cytotoxicity) onthose cells.

A wide variety of compositions and methods for using antibody-cytotoxicagent conjugates to kill cells are known in the art. In the context ofcancers, typical methods entail administering to an mammal having atumor a biologically effective amount of a conjugate comprising aselected cytotoxic and/or therapeutic agent linked to a targeting agent(e.g. a 191P4D12 MAb, preferably Ha22-2(2,4)6.1) that binds to anantigen (e.g. 191P4D12) expressed, accessible to binding or localized onthe cell surfaces. A typical embodiment is a method of delivering acytotoxic and/or therapeutic agent to a cell expressing 191P4D12,comprising conjugating the cytotoxic agent to an antibody thatimmunospecifically binds to a 191P4D12 epitope, and, exposing the cellto the antibody drug conjugate (ADC). Another illustrative embodiment isa method of treating an individual suspected of suffering frommetastasized cancer, comprising a step of administering parenterally tosaid individual a pharmaceutical composition comprising atherapeutically effective amount of an antibody conjugated to acytotoxic and/or therapeutic agent.

Cancer immunotherapy using 191P4D12 antibodies can be done in accordancewith various approaches that have been successfully employed in thetreatment of other types of cancer, including but not limited to coloncancer (Arlen et al., 1998, Crit. Rev. Immunol. 18:133-138), multiplemyeloma (Ozaki et al., 1997, Blood 90:3179-3186, Tsunenari et al., 1997,Blood 90:2437-2444), gastric cancer (Kasprzyk et al., 1992, Cancer Res.52:2771-2776), B-cell lymphoma (Funakoshi et al., 1996, J. Immunother.Emphasis Tumor Immunol. 19:93-101), leukemia (Zhong et al., 1996, Leuk.Res. 20:581-589), colorectal cancer (Moun et al., 1994, Cancer Res.54:6160-6166; Velders et al., 1995, Cancer Res. 55:4398-4403), andbreast cancer (Shepard et al., 1991, J. Clin. Immunol. 11:117-127). Sometherapeutic approaches involve conjugation of naked antibody to a toxinor radioisotope, such as the conjugation of Y⁹¹ or I¹³¹ to anti-CD20antibodies (e.g., Zevalin™, IDEC Pharmaceuticals Corp. or Bexxar™Coulter Pharmaceuticals) respectively, while others involveco-administration of antibodies and other therapeutic agents, such asHerceptin™ (trastuzu MAb) with paclitaxel (Genentech, Inc.). In apreferred embodiment, the antibodies will be conjugated a cytotoxicagent, supra, preferably an aurastatin derivative designated MMAE(Seattle Genetics, Inc).

Although 191P4D12 antibody therapy is useful for all stages of cancer,antibody therapy can be particularly appropriate in advanced ormetastatic cancers. Treatment with the antibody therapy of the inventionis indicated for patients who have received one or more rounds ofchemotherapy. Alternatively, antibody therapy of the invention iscombined with a chemotherapeutic or radiation regimen for patients whohave not received chemotherapeutic treatment. Additionally, antibodytherapy can enable the use of reduced dosages of concomitantchemotherapy, particularly for patients who do not tolerate the toxicityof the chemotherapeutic agent very well. Fan et al. (Cancer Res.53:4637-4642, 1993), Prewett et al. (International J. of Onco.9:217-224, 1996), and Hancock et al. (Cancer Res. 51:4575-4580, 1991)describe the use of various antibodies together with chemotherapeuticagents.

191P4D12 monoclonal antibodies that treat the cancers set forth in TableI include those that initiate a potent immune response against the tumoror those that are directly cytotoxic. In this regard, 191P4D12monoclonal antibodies (MAbs) can elicit tumor cell lysis by eithercomplement-mediated or antibody-dependent cell cytotoxicity (ADCC)mechanisms, both of which require an intact Fc portion of theimmunoglobulin molecule for interaction with effector cell Fc receptorsites on complement proteins. In addition, 191P4D12 MAbs that exert adirect biological effect on tumor growth are useful to treat cancersthat express 191P4D12. Mechanisms by which directly cytotoxic MAbs actinclude: inhibition of cell growth, modulation of cellulardifferentiation, modulation of tumor angiogenesis factor profiles, andthe induction of apoptosis. The mechanism(s) by which a particular191P4D12 MAb exerts an anti-tumor effect is evaluated using any numberof in vitro assays that evaluate cell death such as ADCC,complement-mediated cell lysis, and so forth, as is generally known inthe art.

Accordingly, preferred monoclonal antibodies used in the therapeuticmethods of the invention are those that are either fully human and thatbind specifically to the target 191P4D12 antigen with high affinity.

XIV.) 191P4D12 ADC Cocktails

Therapeutic methods of the invention contemplate the administration ofsingle 191P4D12 ADCs as well as combinations, or cocktails, of differentMAbs (i.e. 191P4D12 MAbs or Mabs that bind another protein). Such MAbcocktails can have certain advantages inasmuch as they contain MAbs thattarget different epitopes, exploit different effector mechanisms orcombine directly cytotoxic MAbs with MAbs that rely on immune effectorfunctionality. Such MAbs in combination can exhibit synergistictherapeutic effects. In addition, 191P4D12 MAbs can be administeredconcomitantly with other therapeutic modalities, including but notlimited to various chemotherapeutic and biologic agents,androgen-blockers, immune modulators (e.g., IL-2, GM-CSF), surgery orradiation. In a preferred embodiment, the 191P4D12 MAbs are administeredin conjugated form.

191P4D12 ADC formulations are administered via any route capable ofdelivering the antibodies to a tumor cell. Routes of administrationinclude, but are not limited to, intravenous, intraperitoneal,intramuscular, intratumor, intradermal, and the like. Treatmentgenerally involves repeated administration of the 191P4D12 ADCpreparation, via an acceptable route of administration such asintravenous injection (IV), typically at a dose in the range, includingbut not limited to, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2,3, 4, 5, 6, 7, 8, 9, 10, 15, 20, or 25 mg/kg body weight. In general,doses in the range of 10-1000 mg MAb per week are effective and welltolerated.

Based on clinical experience with the Herceptin® (Trastuzumab) in thetreatment of metastatic breast cancer, an initial loading dose ofapproximately 4 mg/kg patient body weight IV, followed by weekly dosesof about 2 mg/kg IV of the MAb preparation represents an acceptabledosing regimen. Preferably, the initial loading dose is administered asa 90-minute or longer infusion. The periodic maintenance dose isadministered as a 30 minute or longer infusion, provided the initialdose was well tolerated. As appreciated by those of skill in the art,various factors can influence the ideal dose regimen in a particularcase. Such factors include, for example, the binding affinity and halflife of the MAbs used, the degree of 191P4D12 expression in the patient,the extent of circulating shed 191P4D12 antigen, the desiredsteady-state antibody concentration level, frequency of treatment, andthe influence of chemotherapeutic or other agents used in combinationwith the treatment method of the invention, as well as the health statusof a particular patient.

Optionally, patients should be evaluated for the levels of 191P4D12 in agiven sample (e.g. the levels of circulating 191P4D12 antigen and/or191P4D12 expressing cells) in order to assist in the determination ofthe most effective dosing regimen, etc. Such evaluations are also usedfor monitoring purposes throughout therapy, and are useful to gaugetherapeutic success in combination with the evaluation of otherparameters (for example, urine cytology and/or ImmunoCyt levels inbladder cancer therapy, or by analogy, serum PSA levels in prostatecancer therapy).

An object of the present invention is to provide 191P4D12 ADCs, whichinhibit or retard the growth of tumor cells expressing 191P4D12. Afurther object of this invention is to provide methods to inhibitangiogenesis and other biological functions and thereby reduce tumorgrowth in mammals, preferably humans, using such 191P4D12 ADCs, and inparticular using such 191P4D12 ADCs combined with other drugs orimmunologically active treatments.

XV.) Combination Therapy

In one embodiment, there is synergy when tumors, including human tumors,are treated with 191P4D12 ADCs in conjunction with chemotherapeuticagents or radiation or combinations thereof. In other words, theinhibition of tumor growth by a 191P4D12 ADC is enhanced more thanexpected when combined with chemotherapeutic agents or radiation orcombinations thereof. Synergy may be shown, for example, by greaterinhibition of tumor growth with combined treatment than would beexpected from a treatment of only 191P4D12 ADC or the additive effect oftreatment with a 191P4D12 ADC and a chemotherapeutic agent or radiation.Preferably, synergy is demonstrated by remission of the cancer whereremission is not expected from treatment either from a 191P4D12 ADC orwith treatment using an additive combination of a 191P4D12 ADC and achemotherapeutic agent or radiation.

The method for inhibiting growth of tumor cells using a 191P4D12 ADC anda combination of chemotherapy or radiation or both comprisesadministering the 191P4D12 ADC before, during, or after commencingchemotherapy or radiation therapy, as well as any combination thereof(i.e. before and during, before and after, during and after, or before,during, and after commencing the chemotherapy and/or radiation therapy).For example, the 191P4D12 ADC is typically administered between 1 and 60days, preferably between 3 and 40 days, more preferably between 5 and 12days before commencing radiation therapy and/or chemotherapy. However,depending on the treatment protocol and the specific patient needs, themethod is performed in a manner that will provide the most efficacioustreatment and ultimately prolong the life of the patient.

The administration of chemotherapeutic agents can be accomplished in avariety of ways including systemically by the parenteral and enteralroutes. In one embodiment, the 191P4D12 ADCs and the chemotherapeuticagent are administered as separate molecules. Particular examples ofchemotherapeutic agents or chemotherapy include cisplatin, dacarbazine(DTIC), dactinomycin, mechlorethamine (nitrogen mustard), streptozocin,cyclophosphamide, carmustine (BCNU), lomustine (CCNU), doxorubicin(adriamycin), daunorubicin, procarbazine, mitomycin, cytarabine,etoposide, methotrexate, 5-fluorouracil, vinblastine, vincristine,bleomycin, paclitaxel (taxol), docetaxel (taxotere), aldesleukin,asparaginase, busulfan, carboplatin, cladribine, dacarbazine,floxuridine, fludarabine, hydroxyurea, ifosfamide, interferon alpha,leuprolide, megestrol, melphalan, mercaptopurine, plicamycin, mitotane,pegaspargase, pentostatin, pipobroman, plicamycin, streptozocin,tamoxifen, teniposide, testolactone, thioguanine, thiotepa, uracilmustard, vinorelbine, gemcitabine, chlorambucil, taxol and combinationsthereof.

The source of radiation, used in combination with a 191P4D12 ADC, can beeither external or internal to the patient being treated. When thesource is external to the patient, the therapy is known as external beamradiation therapy (EBRT). When the source of radiation is internal tothe patient, the treatment is called brachytherapy (BT).

The above described therapeutic regimens may be further combined withadditional cancer treating agents and/or regimes, for example additionalchemotherapy, cancer vaccines, signal transduction inhibitors, agentsuseful in treating abnormal cell growth or cancer, antibodies (e.g.Anti-CTLA-4 antibodies as described in WO/2005/092380 (Pfizer)) or otherligands that inhibit tumor growth by binding to IGF-1R, and cytokines.

When the mammal is subjected to additional chemotherapy,chemotherapeutic agents described above may be used. Additionally,growth factor inhibitors, biological response modifiers, anti-hormonaltherapy, selective estrogen receptor modulators (SERMs), angiogenesisinhibitors, and anti-androgens may be used. For example, anti-hormones,for example anti-estrogens such as Nolvadex (tamoxifen) or,anti-androgens such as Casodex(4′-cyano-3-(4-fluorophenylsulphonyl)-2-hydroxy-2-methyl-3-′-(trifluoromethyl)propionanilide)may be used.

The above therapeutic approaches can be combined with any one of a widevariety of surgical, chemotherapy or radiation therapy regimens. Thetherapeutic approaches of the invention can enable the use of reduceddosages of chemotherapy (or other therapies) and/or less frequentadministration, an advantage for all patients and particularly for thosethat do not tolerate the toxicity of the chemotherapeutic agent well.

XVI.) Kits/Articles of Manufacture

For use in the laboratory, prognostic, prophylactic, diagnostic andtherapeutic applications described herein, kits are within the scope ofthe invention. Such kits can comprise a carrier, package, or containerthat is compartmentalized to receive one or more containers such asvials, tubes, and the like, each of the container(s) comprising one ofthe separate elements to be used in the method, along with a label orinsert comprising instructions for use, such as a use described herein.For example, the container(s) can comprise an antibody that is or can bedetectably labeled. Kits can comprise a container comprising a DrugUnit. The kit can include all or part of the amino acid sequences inFIG. 2, or FIG. 3 or analogs thereof, or a nucleic acid molecule thatencodes such amino acid sequences.

The kit of the invention will typically comprise the container describedabove and one or more other containers associated therewith thatcomprise materials desirable from a commercial and user standpoint,including buffers, diluents, filters, needles, syringes; carrier,package, container, vial and/or tube labels listing contents and/orinstructions for use, and package inserts with instructions for use.

A label can be present on or with the container to indicate that thecomposition is used for a specific therapy or non-therapeuticapplication, such as a prognostic, prophylactic, diagnostic orlaboratory application, and can also indicate directions for either invivo or in vitro use, such as those described herein. Directions and orother information can also be included on an insert(s) or label(s) whichis included with or on the kit. The label can be on or associated withthe container. A label a can be on a container when letters, numbers orother characters forming the label are molded or etched into thecontainer itself; a label can be associated with a container when it ispresent within a receptacle or carrier that also holds the container,e.g., as a package insert. The label can indicate that the compositionis used for diagnosing, treating, prophylaxing or prognosing acondition, such as a cancer of a tissue set forth in Table I.

The terms “kit” and “article of manufacture” can be used as synonyms.

In another embodiment of the invention, an article(s) of manufacturecontaining compositions, such as antibody(s), or antibody drugconjugates (ADCs) e.g., materials useful for the diagnosis, prognosis,prophylaxis and/or treatment of cancers of tissues such as those setforth in Table I is provided. The article of manufacture typicallycomprises at least one container and at least one label. Suitablecontainers include, for example, bottles, vials, syringes, and testtubes. The containers can be formed from a variety of materials such asglass, metal or plastic. The container can hold amino acid sequence(s),small molecule(s), nucleic acid sequence(s), cell population(s) and/orantibody(s). In another embodiment a container comprises an antibody,binding fragment thereof or specific binding protein for use inevaluating protein expression of 191P4D12 in cells and tissues, or forrelevant laboratory, prognostic, diagnostic, prophylactic andtherapeutic purposes; indications and/or directions for such uses can beincluded on or with such container, as can reagents and othercompositions or tools used for these purposes.

The container can alternatively hold a composition that is effective fortreating, diagnosis, prognosing or prophylaxing a condition and can havea sterile access port (for example the container can be an intravenoussolution bag or a vial having a stopper pierceable by a hypodermicinjection needle). The active agents in the composition can be anantibody capable of specifically binding 191P4D12 or an antibody drugconjugate specifically binding to 191P4D12.

The article of manufacture can further comprise a second containercomprising a pharmaceutically-acceptable buffer, such asphosphate-buffered saline, Ringer's solution and/or dextrose solution.It can further include other materials desirable from a commercial anduser standpoint, including other buffers, diluents, filters, stirrers,needles, syringes, and/or package inserts with indications and/orinstructions for use.

EXAMPLES

Various aspects of the invention are further described and illustratedby way of the several examples that follow, none of which is intended tolimit the scope of the invention.

Example 1 The 191P4D12 Antigen

The 191P4D12 gene sequence was discovered using Suppression SubtractiveHybridization (SSH) methods known in the art. The 191P4D12 SSH sequenceof 223 by was identified from a bladder tumor minus cDNAs derived from apool of nine (9) normal tissues using standard methods. A full lengthcDNA clone for 191P4D12 was isolated from a bladder cancer cDNA library.The cDNA is 3464 by in length and encodes a 510 amino acid ORF (See,FIG. 1). The 191P4D12 gene shows homology to Nectin-4 gene. For furtherreference see, US2004/0083497 (Agensys, Inc., Santa Monica, Calif.) andPCT Publication WO2004/016799 (Agensys, Inc., Santa Monica, Calif.). Forexemplary embodiments of the 191P4D12 antigen, see FIG. 1.

Example 2 Generation of 191P4D12 Monoclonal Antibodies (MAbs)

In one embodiment, therapeutic Monoclonal Antibodies (“MAbs”) to191P4D12 and 191P4D12 variants comprise those that react with epitopesspecific for each protein or specific to sequences in common between thevariants that would bind, internalize, disrupt or modulate thebiological function of 191P4D12 or 191P4D12 variants, for example, thosethat would disrupt the interaction with ligands, substrates, and bindingpartners. Immunogens for generation of such MAbs include those designedto encode or contain the extracellular domains or the entire 191P4D12protein sequence, regions predicted to contain functional motifs, andregions of the 191P4D12 protein variants predicted to be antigenic fromcomputer analysis of the amino acid sequence Immunogens include peptidesand recombinant proteins such as tag5-191P4D12, a purified mammaliancell derived His tagged protein. In addition, cells engineered toexpress high levels of 191P4D12, such as RAT1-191P4D12 or300.19-191P4D12, are used to immunize mice.

MAbs to 191P4D12 were generated using XenoMouse technology® (AmgemFremont) wherein the murine heavy and kappa light chain loci have beeninactivated and a majority of the human heavy and kappa light chainimmunoglobulin loci have been inserted. The MAb designatedHa22-2(2,4)6.1 was generated from immunization of human γ1 producingXenoMice with pTag5/mychis-191P4D12 (amino acids 23-351).

The 191P4D12 MAb Ha22-2(2,4)6.1 specifically binds topTag5/mychis-191P4D12 protein by ELISA as well as recombinant 191P4D12expressing cells and multiple cancer cell lines expressing 191P4D12.

The hybridoma producing an antibody designated Ha22-2(2,4)6.1 was sent(via Federal Express) to the American Type Culture Collection (ATCC),P.O. Box 1549, Manassas, Va. 20108 on 18 Aug. 2010 and assignedAccession number PTA-11267.

DNA coding sequences for 191P4D12 MAb Ha22-2(2,4)6.1 was determinedafter isolating mRNA from the respective hybridoma cells with Trizolreagent (Life Technologies, Gibco BRL).

Anti-191P4D12 Ha22-2(2,4)6.1 heavy and light chain variable nucleic acidsequences were sequenced from the hybridoma cells using the followingprotocol. Ha22-2(2,4)6.1 secreting hybridoma cells were lysed withTrizol reagent (Life Technologies, Gibco BRL). Total RNA was purifiedand quantified. First strand cDNAs was generated from total RNA witholigo (dT)12-18 priming using the Gibco-BRL Superscript Preamplificationsystem. First strand cDNA was amplified using human immunoglobulinvariable heavy chain primers, and human immunoglobulin variable lightchain primers. PCR products were sequenced and the variable heavy andlight chain regions determined

The nucleic acid and amino acid sequences of the variable heavy andlight chain regions are listed in FIG. 2 and FIG. 3. Alignment ofHa22-2(2,4)6.1 MAb to human Ig germline is set forth in FIG. 4A-4B.

Example 3 Expression of Ha22-2(2,4)6.1 Using Recombinant DNA Methods

To express Ha22-2(2,4)6.1 MAb recombinantly in transfected cells,Ha22-2(2,4)6.1 MAb variable heavy and light chain sequences were clonedupstream of the human heavy chain IgG1 and human light chain Igκconstant regions respectively. The complete Ha22-2(2,4)6.1 MAb humanheavy chain and light chain cassettes were cloned downstream of the CMVpromoter/enhancer in a cloning vector. A polyadenylation site wasincluded downstream of the MAb coding sequence. The recombinantHa22-2(2,4)6.1 MAb expressing constructs were transfected into CHOcells. The Ha22-2(2,4)6.1 MAb secreted from recombinant cells wasevaluated for binding to cell surface 191P4D12 by flow cytometry (FIG.5A). RAT-control and RAT-191P4D12 cells were stained with Ha22-2(2,4)6.1MAb from either hybridoma or from CHO cells transfected withHa22-2(2,4)6.1 heavy and light chain vector constructs. Binding wasdetected by flow cytometry.

Results show that the recombinantly expressed Ha22-2(2,4)6.1 expressedin CHO cells binds 191P4D12 similarly to the Ha22-2(2,4)6.1 purifiedfrom hybridoma. The Ha22-2(2,4)6.1 MAb secreted from recombinant cellswas also evaluated for binding to 191P4D12 recombinant protein by ELISA.As shown in FIG. 5B, binding of Ha22-2(2,4)6.1 to 191P4D12 protein wasidentical between MAb material derived from CHO and from hybridomacells.

Example 4 Antibody Drug Conjugation of Ha22-2(2,4)6.1 MAb

The Ha22-2(2,4)6.1 Mab (FIG. 2) was conjugated to an auristatinderivative designated MMAE (Formula XI) using a vc (Val-Cit) linkerdescribed herein to create the antibody drug conjugate (ADC) of theinvention designated Ha22-2(2,4)6.1vcMMAE using the following protocols.The conjugation of the vc (Val-Cit) linker to the MMAE (SeattleGenetics, Inc., Seattle, Wash.) was completed using the general methodset forth in Table IV to create the cytotoxic vcMMAE (see, U.S. Pat. No.7,659,241).

Next, the antibody drug conjugate (ADC) of the invention designatedHa22-2(2,4)6.1vcMMAE was made using the following protocols.

Briefly, a 15 mg/mL solution of the Ha22-2(2,4)6.1MAb in 10 mM acetateat pH 5.0, 1% sorbitol, 3% L-agrinine is added with a 20% volume of 0.1M TrisCl at pH 8.4, 25 mM EDTA and 750 mM NaCl to adjust the pH of thesolution to 7.5, 5 mM EDTA and 150 mM sodium chloride. The MAb is thenpartially reduced by adding 2.3 molar equivalents of TCEP (relative tomoles of MAb) and then stirred at 37° C. for 2 hours. The partiallyreduced MAb solution is then cooled to 5° C. and 4.4 molar equivalentsof vcMMAE (relative to moles of antibody) are added as a 6% (v/v)solution of DMSO. The mixture is stirred for 60 minutes at 5° C., thenfor 15 additional minutes following the addition of 1 molar equivalentsof N-acetylcysteine relative to vcMMAE. Excess quenched vcMMAE and otherreaction components are removed by ultrafiltration/diafiltration of theantibody drug conjugate (ADC) with 10 volumes of 20 mM histidine, pH6.0.

The resulting antibody drug conjugate (ADC) is designatedHa22-2(2,4)6.1vcMMAE and has the following formula:

-   -   wherein MAb is Ha22-2(2,4)6.1 (FIG. 2 and FIG. 3) and p is from        1 to 8. The p value of the antibody drug conjugate set forth in        this Example was about 3.8.

Example 5 Characterization of Ha22-2(2,4)6.1vcMMAE

Antibody Drug Conjugates that bind 191P4D12 were generated using theprocedures set forth in the example entitled “Antibody Drug Conjugationof Ha22-2(2,4)6.1 MAb” and were screened, identified, and characterizedusing a combination of assays known in the art.

A. Affinity Determination by FACS

Ha22-2(2,4)6.1vcMMAE was tested for its binding affinity to 191P4D12expressed on the surface of PC3-human-191P4D12, PC3-Cynomolgus-191P4D12,and PC3-rat-191P4D12 cells respectively. Briefly, eleven (11) dilutionsof Ha22-2(2,4)6.1vcMMAE were incubated with each of the cell types(50,000 cells per well) overnight at 4° C. at a final concentration of160 nM to 0.011 nM. At the end of the incubation, cells are washed andincubated with anti-hIgG-PE detection antibody for 45 min at 4° C. Afterwashing the unbound detection antibodies, the cells are analyzed byFACS. Mean Florescence Intensity (MFI) values were obtained as listed inFIGS. 6-8. MFI values were entered into Graphpad Prisim software andanalyzed using the one site binding (hyperbola) equation ofY=Bmax*X/(Kd+X) to generate Ha22-2(2,4)6.1vcMMAE saturation curves shownalso in FIGS. 6-8 respectively. Bmax is the MFI value at maximal bindingof Ha22-2(2,4)6.1vcMMAE to 191P4D12; Kd is the Ha22-2(2,4)6.1vcMMAEbinding affinity which is the concentration of Ha22-2(2,4)6.1vcMMAErequired to reach half-maximal binding.

The calculated affinity (Kd) of Ha22-2(2,4)6.1vcMMAE to 191P4D12expressed on the surface of PC3-human-191P4D12, PC3-Cynomolgus-191P4D12,and PC3-rat-191P4D12 cells respectively is 0.69 nM (FIG. 6), 0.34 nM(FIG. 7), and 1.6 nM (FIG. 8).

B. Affinity Determination by SPR

The affinity of Ha22-2(2,4)6.1 MAb and Ha22-2(2,4)6.1vcMMAE to purifiedrecombinant 191P4D12 (ECD amino acids 1-348) was performed by SurfacePlasmon Resonance (SPR) (BIAcore). Briefly, goat-anti-human Fcγpolyclonal Abs (Jackson Immuno Research Labs, Inc.) were covalentlyimmobilized on the surface of a CM5 sensor chip (Biacore). PurifiedHa22-2(2,4)6.1 MAb or Ha22-2(2,4)6.1vcMMAE were then captured on thesurface of said chip. On average, approximately 300 RUs of testHa22-2(2,4)6.1 MAb or Ha22-2(2,4)6.1vcMMAE was captured in every cycle.Subsequently, a series of five (5) to six (6) dilutions of recombinant191P4D12 (ECD amino acids 1-348) ranging from 1 nM to 100 nM wasinjected over such surface to generate binding curves (sensograms) thatwere processed and globally fit to a 1:1 interaction model usingBIAevaluation 3.2 and CLAMP software (Myszka and Morton, 1998) (FIG.22). Table V summarizes association and dissociation rate constants aswell as affinities of Ha22-2(2,4)6.1 MAb and Ha22-2(2,4)6.1vcMMAE torecombinant 191P4D12 (ECD amino acids 1-348).

C. Domain Mapping of Ha22-2(2,4)6.1 MAb

To map the binding site of Ha22-2(2,4)6.1 MAb to a specific domain of191P4D12 protein, several Rat1(E) recombinant cell lines expressing suchdomains (or a combination thereof) were generated (Table VI). Binding ofHa22-2(2,4)6.1 to cell surface was assessed by FACS using standardprotocols. As shown in FIG. 10, Ha22-2(2,4)6.1 MAb binds to VC1 domainexpressing cells as well as wild-type 191P4D12, but not to C1C2 domainexpressing cells. Additionally, another 191P4D12 MAb entitled Ha22-8e6.1recognizes C1C2 domain of 191P4D12 on cell surface, but not the VC1domain. This suggests that the binding site for Ha22-2(2,4)6.1 MAb islocated in the 1-147 aa domain of 191P4D12, but that not every MAb whichbinds to 191P4D12 recognizes this domain.

To further corroborate the results set forth in FIG. 10, a Western Blotanalysis was performed. Briefly, the entire extracellular portion of191P4D12 (full length), as well as specific domains set forth in TableVI were expressed in 293T cells as murine Fc fusion proteins andpurified. Goat anti-mouse-HRP were used as a control. As shown in FIG.11, when resolved on SDS-PAGE (non-reduced) and probed withHa22-2(2,4)6.1-biotin followed by streptavidin-HRP, bands correspondingto full-length 191P4D12 (lane 1), V (lane 2) and VC1 (lane 3) fusionconstructs, but not C1C2 fusion construct (lane 4) are recognized. Thisfurther suggests that the binding epitope for Ha22-2(2,4)6.1 MAb islocated within 1-147 aa domain of 191P4D12.

Example 6 Cell Cytotoxicity Mediated by Ha22-2(2,4)6.1vcMMAE

The ability of Ha22-2(2,4)6.1vcMMAE to mediate 191P4D12-dependentcytotoxicity was evaluated in PC3 cells engineered to express human191P4D12, Cynomolgus 191P4D12 and rat 191P4D12. Briefly, PC3-Neo,PC3-human-191P4D12 cells, PC3-Cynomolgus-191P4D12 or PC3-rat-191P4D12cells (1500 cells/well) were seeded into a 96 well plate on day 1. Thefollowing day an equal volume of medium containing the indicatedconcentration of Ha22-2(2,4)6.1vcMMAE or a Control MAb conjugated withvcMMAE (i.e. Control-vcMMAE) was added to each well. The cells wereallowed to incubate for 4 days at 37 degrees C. At the end of theincubation period, Alamar Blue was added to each well and incubationcontinued for an additional 4 hours. The resulting fluorescence wasdetected using a Biotek plate reader with an excitation wavelength of620 nM and an emission wavelength of 540 nM.

The results in FIG. 9A-9D show that Ha22-2(2,4)6.1vcMMAE mediatedcytotoxicity in PC3-human-191P4D12 (FIG. 9A), PC3-Cynomolgus-191P4D12(FIG. 9B), and PC3-rat-191P4D12 cells (FIG. 9C) while a control humanIgG conjugated with vcMMAE had no effect. The specificity ofHa22-2(2,4)6.1vcMMAE was further demonstrated by the lack of toxicityfor PC3-Neo cells that do not express 191P4D12 (FIG. 9D). Thus, theseresults indicate that Ha22-2(2,4)6.1vcMMAE can selectively deliver acytotoxic drug to 191P4D12 expressing cells leading to their killing.

Example 7 Ha22-2(2,4)6.1vcMMAE Inhibit Growth of Tumors In Vivo

The significant expression of 191P4D12 on the cell surface of tumortissues, together with its restrictive expression in normal tissuesmakes 191P4D12 a good target for antibody therapy and similarly, therapyvia ADC. Thus, the therapeutic efficacy of Ha22-2(2,4)6.1vcMMAE in humanbladder, lung, breast, and pancreatic cancer xenograft mouse models isevaluated.

Antibody drug conjugate efficacy on tumor growth and metastasisformation is studied in mouse cancer xenograft models (e.g. subcutaneousand orthotopically).

Subcutaneous (s.c.) tumors are generated by injection of 5×10⁴-10⁶cancer cells mixed at a 1:1 dilution with Matrigel (CollaborativeResearch) in the right flank of male SCID mice. To test ADC efficacy ontumor formation, ADC injections are started on the same day astumor-cell injections. As a control, mice are injected with eitherpurified human IgG or PBS; or a purified MAb that recognizes anirrelevant antigen not expressed in human cells. In preliminary studies,no difference is found between control IgG or PBS on tumor growth. Tumorsizes are determined by caliper measurements, and the tumor volume iscalculated as width²×Length/2, wherein width is the smallest dimensionand length is the largest dimension. Mice with subcutaneous tumorsgreater than 1.5 cm in diameter are sacrificed.

Ovarian tumors often metastasize and grow within the peritoneal cavity.Accordingly, intraperitoneal growth of ovarian tumors in mice areperformed by injection of 2 million cells directly into the peritoneumof female mice. Mice are monitored for general health, physicalactivity, and appearance until they become moribund. At the time ofsacrifice, the peritoneal cavity can be examined to determine tumorburden and lungs harvested to evaluate metastasis to distant sites.Alternatively, death can be used as an endpoint. The mice are thensegregated into groups for the appropriate treatments, with 191P4D12 orcontrol MAbs being injected i.p.

An advantage of xenograft cancer models is the ability to studyneovascularization and angiogenesis. Tumor growth is partly dependent onnew blood vessel development. Although the capillary system anddeveloping blood network is of host origin, the initiation andarchitecture of the neovasculature is regulated by the xenograft tumor(Davidoff et al., Clin Cancer Res. (2001) 7:2870; Solesvik et al., Eur JCancer Clin Oncol. (1984) 20:1295). The effect of antibody and smallmolecule on neovascularization is studied in accordance with proceduresknown in the art, such as by IHC analysis of tumor tissues and theirsurrounding microenvironment.

Ha22-2(2,4)6.1ADC inhibits formation lung, bladder, breast, andpancreatic cancer xenografts. These results indicate the utility ofHa22-2(2,4)6.1ADC in the treatment of local and advanced stages ofcancer and preferably those cancers set forth in Table I.

191P4D12 ADCs:

Monoclonal antibodies were raised against 191P4D12 as described in theExample entitled “Generation of 191P4D12 Monoclonal Antibodies (MAbs).”Further the MAbs are conjugated to a toxin as described in the Exampleentitled “Antibody Drug Conjugation of Ha22-2(2,4)6.1 MAb” to formHa22-2(2,4)6.1vcMMAE. The Ha22-2(2,4)6.1vcMMAE is characterized by FACS,and other methods known in the art to determine its capacity to bind191P4D12.

Cell Lines and Xenografts:

The BT-483 and HPAC cells are maintained in DMEM, supplemented withL-glutamine and 10% FBS, as known in the art. AG-B8, AG-Panc4, AG-Panc2,AG-B1, AG-L4, and AG-Panc3 xenografts are maintained by serialpropagation in SCID mice.

Evaluation of Ha22-2(2,4)6.1vcMMAE MAb in the Subcutaneous TumorFormation Model of Human Lung Cancer Xenograft AG-L4 in SCID Mice

In this experiment, patient-derived lung cancer xenograft AG-L4 wasmaintained by serial passages in SCID mice. Stock tumors were harvestedsterilely and enzymatically digested into single cell suspensions. Two(2) million cells were implanted into the flank of individual SCID mice.Animals were then randomly assigned to seven groups: six (6) 191P4D12antibody treated groups and a control antibody H3-1.10.1.2 group (n=10).All antibodies were dosed intraperitoneally at 750 μg/animal twice aweek until the end of the study. Tumor growth was monitored usingcaliper measurements every 3 to 4 days. Tumor volume was calculated asWidth²×Length/2, where width is the smallest dimension and length is thelargest dimension.

The results show that the 191P4D12 MAb did not significantly inhibittumor growth in human lung cancer xenograft AG-L4 in SCID mice.Additionally, other 191P4D12 MAbs were utilized in this study. Theresults are not shown. (FIG. 12).

Evaluation of Ha22-2(2,4)6.1 MAb in the Subcutaneous Tumor FormationModel of Human Pancreatic Cancer Xenograft HPAC in SCID Mice

In another experiment, human pancreatic cancer HPAC cells (2.0millions/mouse) were injected into the flank of individual SCID miceAnimals were then randomly assigned to eight groups: seven (7) 191P4D12antibody treated groups and a control antibody H3-1.4.1.2 group (n=10).All antibodies were dosed intraperitoneally at 500 μg/animal twice aweek until the end of the study. Tumor growth was monitored usingcaliper measurements every 3 to 4 days. Tumor volume was calculated asWidth²×Length/2, where width is the smallest dimension and length is thelargest dimension.

The results show that the 191P4D12 MAb did not inhibit tumor growth in ahuman pancreatic xenograft in SCID mice when compared to the controlantibody. Additionally, other 191P4D12 MAbs were utilized in this study.The results are not shown. (FIG. 13).

Evaluation of Ha22-2(2,4)6.1 MAb in the subcutaneous tumor formationmodel of human pancreatic cancer xenograft AG-Panc3 in SCID mice.

In another experiment, patient-derived pancreatic cancer xenograftAG-Panc3 was maintained by serial passages in SCID mice. Stock tumorswere harvested sterilely and minced into 1 mm³ pieces. Six pieces wereimplanted into the flank of individual SCID mice. Animals were thenrandomly assigned to the following cohorts (n=10): two (2) 191P4D12 MAbtreated groups and a control antibody H3-1.4.1.2 group. All antibodieswere dosed intraperitoneally at 500 μg/animal twice a week until the endof the study. Tumor growth was monitored using caliper measurementsevery 3 to 4 days. Tumor volume was calculated as Width²×Length/2, wherewidth is the smallest dimension and length is the largest dimension.

The results show that the 191P4D12 MAb did not inhibit tumor growth in ahuman pancreatic xenograft in SCID mice when compared to the controlantibody. Additionally, other 191P4D12 MAbs were utilized in this study.The results are not shown. (FIG. 14).

Efficacy of Ha22-2(2,4)6.1-vcMMAE in Subcutaneous Established Human LungCancer Xenograft AG-LA in SCID Mice

In another experiment, patient-derived lung cancer xenograft AG-L13 wasmaintained by serial passages in SCID mice. Stock tumors were harvestedsterilely and minced into 1 mm³ pieces. Six (6) pieces were implantedinto the flank of individual SCID mice. Tumors were allowed to growuntreated until they reached an approximate volume of 200 mm³. TheHa22-2(2,4)6.1vcMMAE and the control ADC were dosed at 10 mg/kg everyseven (7) days for two doses by intravenous bolus injection. The amountof ADC administered was based on the individual body weight of eachanimal obtained immediately prior to dosing. Tumor growth was monitoredusing caliper measurements every 3 to 4 days. Tumor volume wascalculated as Width²×Length/2, where width is the smallest dimension andlength is the largest dimension.

The results show that treatment with Ha22-2(2,4)6.1-vcMMAE significantlyinhibited the growth of AG-L4 lung cancer xenografts implantedsubcutaneously in nude mice compared to the control ADC. Additionally,other 191P4D12 MAbs were utilized in this study. The results are notshown. (FIG. 15).

Efficacy of Ha22-2(2,4)6.1-vcMMAE in Subcutaneous Established HumanBreast Cancer Xenograft BT-483 in SCID Mice

In this experiment, human breast cancer BT-483 cells were used togenerate stock xenografts, which were maintained by serial passages inSCID mice. Stock tumors were harvested sterilely and minced into 1 mm³pieces. Six (6) pieces were implanted into the flank of individual SCIDmice. Tumors were allowed to grow untreated until they reached anapproximate volume of 100 mm³ The Ha22-2(2,4)6.1vcMMAE and the controlADC were dosed at 5 mg/kg every four (4) days for four (4) doses byintravenous bolus injection. The amount of ADC administered was based onthe individual body weight of each animal obtained immediately prior todosing. Tumor growth was monitored using caliper measurements every 3 to4 days. Tumor volume was calculated as Width²×Length/2, where width isthe smallest dimension and length is the largest dimension.

The results show that treatment with Ha22-2(2,4)6.1-vcMMAE significantlyinhibited the growth of BT-483 breast tumor xenografts implantedsubcutaneously in SCID mice compared to the control ADC. Additionally,other 191P4D12 MAbs were utilized in this study. The results are notshown. (FIG. 16).

Efficacy of Ha22-2(2,4)6.1-vcMMAE in Subcutaneous Established HumanBladder Cancer Xenograft AG-B1 in SCID Mice

In another experiment, patient-derived bladder cancer xenograft AG-B1was maintained by serial passages in SCID mice. Stock tumors wereharvested sterilely and minced into 1 mm³ pieces. Six (6) pieces wereimplanted into the flank of individual SCID mice. Tumors were allowed togrow untreated until they reached an approximate volume of 230 mm³. TheHa22-2(2,4)6.1vcMMAE and the control ADC were dosed at 4 mg/kg once byintravenous bolus injection. The amount of ADC administered was based onthe individual body weight of each animal obtained immediately prior todosing. Tumor growth was monitored using caliper measurements every 3 to4 days. Tumor volume was calculated as Width²×Length/2, where width isthe smallest dimension and length is the largest dimension.

The results show that treatment with Ha22-2(2,4)6.1-vcMMAE significantlyinhibited the growth of AG-B1 bladder cancer xenografts as compared tothe control ADC. Additionally, other 191P4D12 MAbs were utilized in thisstudy. The results are not shown. (FIG. 17).

Efficacy of Ha22-2(2,4)6.1-vcMMAE in Subcutaneous Established HumanPancreatic Cancer Xenograft AG-Panc2 in SCID Mice

In another experiment, patient-derived pancreatic cancer xenograftAG-Panc2 was maintained by serial passages in SCID mice. Stock tumorswere harvested sterilely and minced into 1 mm³ pieces. Five (5) pieceswere implanted into the flank of individual SCID mice. Tumors wereallowed to grow untreated until they reached an approximate volume of100 mm³. The Ha22-2(2,4)6.1vcMMAE and control ADC were dosed at 5 mg/kgevery four (4) days for four (4) doses by intravenous bolus injection.The amount of ADC administered was based on the individual body weightof each animal obtained immediately prior to dosing. Tumor growth wasmonitored using caliper measurements every 3 to 4 days. Tumor volume wascalculated as Width²×Length/2, where width is the smallest dimension andlength is the largest dimension.

The results show that treatment with Ha22-2(2,4)6.1-vcMMAE significantlyinhibited the growth of AG-Panc2 pancreatic cancer xenografts ascompared to the control ADC. Additionally, other 191P4D12 MAbs wereutilized in this study. The results are not shown. (FIG. 18).

Efficacy of Ha22-2(2,4)6.1-vcMMAE in Subcutaneous Established HumanPancreatic Cancer Xenograft AG-Panc4 in SCID Mice

In another experiment, patient-derived pancreatic cancer xenograftAG-Panc4 was maintained by serial passages in SCID mice. Stock tumorswere harvested sterilely and minced into 1 mm³ pieces. Six (6) pieceswere implanted into the flank of individual SCID mice. TheHa22-2(2,4)6.1vcMMAE and control ADC were dosed at 5 mg/kg every seven(7) days for three doses by intravenous bolus injection. The amount ofADC administered was based on the individual body weight of each animalobtained immediately prior to dosing. Tumor growth was monitored usingcaliper measurements every 3 to 4 days. Tumor volume was calculated asWidth²×Length/2, where width is the smallest dimension and length is thelargest dimension.

The results show that treatment with Ha22-2(2,4)6.1-vcMMAE significantlyinhibited the growth of AG-Panc4 pancreatic cancer xenografts ascompared to the control ADC. Additionally, other 191P4D12 MAbs wereutilized in this study. The results are not shown. (FIG. 19).

Efficacy of Ha22-2(2,4)6.1-vcMMAE at Comparative Dosage in SubcutaneousEstablished Human Bladder Cancer Xenograft AG-B8 in SCID Mice

In this experiment, patient-derived bladder cancer xenograft AG-B8 wasmaintained by serial passages in SCID mice. Stock tumors were harvestedsterilely and minced into 1 mm³ pieces. Six (6) pieces were implantedinto the flank of individual SCID mice. Tumors were allowed to growuntreated until they reached an approximate volume of 200 mm³ Animalswere then randomly assigned to the following three cohorts (n=6): two(2) Ha22-2(2,4)6.1-vcMMAE treated groups and a control ADCVCD37-5ce5p-vcMMAE group. Ha22-2(2,4)6.1-vcMMAE was dosed at 5 mg/kg or10 mg/kg and the control ADC was given at 5 mg/kg. All ADCs were dosedonce by intravenous bolus injection. The amount of ADC administered wasbased on the individual body weight of each animal obtained immediatelyprior to dosing. Tumor growth was monitored using caliper measurementsevery 3 to 4 days. Tumor volume was calculated as Width²×Length/2, wherewidth is the smallest dimension and length is the largest dimension.

The results show that treatment with Ha22-2(2,4)6.1vcMMAE at 10 mg/kginhibited the growth of AG-B8 bladder cancer xenografts as compared tothe Ha22-2(2,4)6.1vcMMAE at 5 mg/kg. (FIG. 20).

Conclusion

In summary, FIGS. 12-20, show that the 191P4D12 ADC entitledHa22-2(2,4)6.1vcMMAE significantly inhibited the growth of tumors cellsthat express 191P4D12 when compared to control ADCs. Thus, theHa22-2(2,4)6.1vcMMAE can be used for therapeutic purposes to treat andmanage cancers set forth in Table I.

Example 8 Human Clinical Trials for the Treatment and Diagnosis of HumanCarcinomas Through Use of 191P4D12 ADCs

191P4D12 ADCs are used in accordance with the present invention whichspecifically bind to 191P4D12, and are used in the treatment of certaintumors, preferably those listed in Table I. In connection with each ofthese indications, two clinical approaches are successfully pursued.

I.) Adjunctive therapy: In adjunctive therapy, patients are treated with191P4D12 ADCs in combination with a chemotherapeutic or anti-neoplasticagent and/or radiation therapy or a combination thereof. Primary cancertargets, such as those listed in Table I, are treated under standardprotocols by the addition of 191P4D12 ADCs to standard first and secondline therapy. Protocol designs address effectiveness as assessed by thefollowing examples, including but not limited to, reduction in tumormass of primary or metastatic lesions, increased progression freesurvival, overall survival, improvement of patients health, diseasestabilization, as well as the ability to reduce usual doses of standardchemotherapy and other biologic agents. These dosage reductions allowadditional and/or prolonged therapy by reducing dose-related toxicity ofthe chemotherapeutic or biologic agent. 191P4D12 ADCs are utilized inseveral adjunctive clinical trials in combination with thechemotherapeutic or anti-neoplastic agents.

II.) Monotherapy: In connection with the use of the 191P4D12 ADCs inmonotherapy of tumors, the 191P4D12 ADCs are administered to patientswithout a chemotherapeutic or anti-neoplastic agent. In one embodiment,monotherapy is conducted clinically in end-stage cancer patients withextensive metastatic disease. Protocol designs address effectiveness asassessed by the following examples, including but not limited to,reduction in tumor mass of primary or metastatic lesions, increasedprogression free survival, overall survival, improvement of patientshealth, disease stabilization, as well as the ability to reduce usualdoses of standard chemotherapy and other biologic agents.

Dosage

Dosage regimens may be adjusted to provide the optimum desired response.For example, a single bolus may be administered, several divided dosesmay be administered over time or the dose may be proportionally reducedor increased as indicated by the exigencies of the therapeuticsituation. It is especially advantageous to formulate parenteralcompositions in dosage unit form for ease of administration anduniformity of dosage. Dosage unit form as used herein refers tophysically discrete units suited as unitary dosages for the mammaliansubjects to be treated; each unit containing a predetermined quantity ofactive compound calculated to produce the desired therapeutic effect inassociation with the required pharmaceutical carrier. The specificationfor the dosage unit forms of the invention are dictated by and directlydependent on (a) the unique characteristics of the antibody and/or ADCand the particular therapeutic or prophylactic effect to be achieved,and (b) the limitations inherent in the art of compounding such anactive compound for the treatment of sensitivity in individuals.

An exemplary, non limiting range for a therapeutically effective amountof an 191P4D12 ADC administered in combination according to theinvention is about 0.5 to about 10 mg/kg, about 1 to about 5 mg/kg, atleast 1 mg/kg, at least 2 mg/kg, at least 3 mg/kg, or at least 4 mg/kg.Other exemplary non-limiting ranges are for example about 0.5 to about 5mg/kg, or for example about 0.8 to about 5 mg/kg, or for example about 1to about 7.5 mg/kg. The high dose embodiment of the invention relates toa dosage of more than 10 mg/kg. It is to be noted that dosage values mayvary with the type and severity of the condition to be alleviated, andmay include single or multiple doses. It is to be further understoodthat for any particular subject, specific dosage regimens should beadjusted over time according to the individual need and the professionaljudgment of the person administering or supervising the administrationof the compositions, and that dosage ranges set forth herein areexemplary only and are not intended to limit the scope or practice ofthe claimed composition.

Clinical Development Plan (CDP)

The CDP follows and develops treatments of 191P4D12 ADCs in connectionwith adjunctive therapy or monotherapy. Trials initially demonstratesafety and thereafter confirm efficacy in repeat doses. Trials are openlabel comparing standard chemotherapy with standard therapy plus191P4D12 ADCs. As will be appreciated, one non-limiting criteria thatcan be utilized in connection with enrollment of patients is 191P4D12expression levels in their tumors as determined by biopsy.

As with any protein or antibody infusion-based therapeutic, safetyconcerns are related primarily to (i) cytokine release syndrome, i.e.,hypotension, fever, shaking, chills; (ii) the development of animmunogenic response to the material (i.e., development of humanantibodies by the patient to the antibody therapeutic, or HAMAresponse); and, (iii) toxicity to normal cells that express 191P4D12.Standard tests and follow-up are utilized to monitor each of thesesafety concerns. 191P4D12 ADCs are found to be safe upon humanadministration.

Example 9 Detection of 191P4D12 Protein in Cancer Patient Specimens byIHC

Expression of 191P4D12 protein by immunohistochemistry was tested inpatient tumor specimens from (i) bladder, (ii) breast, (iii) pancreatic,(iv) lung, (v) ovarian cancer, (vi) esophageal, and (vii) head and neckpatients. Briefly, formalin fixed, paraffin wax-embedded tissues werecut into four (4) micron sections and mounted on glass slides. Thesections were de-waxed, rehydrated and treated with EDTA antigenretrieval solution (Biogenex, San Ramon, Calif.) in the EZ-Retrievermicrowave (Biogenex, San Ramon, Calif.) for 30 minutes at 95° C.Sections were then treated with 3% hydrogen peroxide solution toinactivate endogenous peroxidase activity. Serum-free protein block(Dako, Carpenteria, Calif.) was used to inhibit non-specific bindingprior to incubation with monoclonal mouse anti-191P4D12 antibody or anisotype control. Subsequently, the sections were treated with the SuperSensitive™ Polymer-horseradish peroxidase (HRP) Detection System whichconsists of an incubation in Super Enhancer™ reagent followed by anincubation with polymer-HRP secondary antibody conjugate (BioGenex, SanRamon, Calif.). The sections were then developed using the DAB kit(BioGenex, San Ramon, Calif.). Nuclei were stained using hematoxylin,and analyzed by bright field microscopy. Specific staining was detectedin patient specimens using the 191P4D12 immunoreactive antibody, asindicated by the brown staining. (See, FIGS. 21(A), 21(C), 21(E), 21(G),21(I), 21(K), and 21(M)). In contrast, the control antibody did notstain either patient specimen. (See, FIGS. 21(B), 21(D), 21(F), 21(H),21(J), 21(L), and 21(N)).

The results show expression of 191P4D12 in the tumor cells of patientbladder, breast, pancreatic, lung, ovarian, esophageal, and head andneck cancer tissues. These results indicate that 191P4D12 is expressedin human cancers and that antibodies directed to this antigen and theantibody drug conjugate designated Ha22-2(2,4)6.1vcMMAE) are useful fordiagnostic and therapeutic purposes. (FIG. 21).

Example 10 Determining the Binding Epitope of Ha22-2(2,4)6.1 MAb

The 191P4D12 protein of human, cynomolgus, rat and murine origin wasoverexpressed recombinantly in a PC3 cell line to determinecross-reactivity of Ha22-2(2,4)6.1 to these orthologs. It was shown thatHa22-2(2,4)6.1 strongly cross-reacts with cynomolgus and rat orthologsof 191P4D12 (FIG. 23). EC50 binding values are shown in Table VII.Binding of Ha22-2(2,4)6.1 to murine ortholog shows a significantreduction in binding EC50 value, which shows important amino acidsubstitutions in the V domain (as compared to human and rat sequences)affected affinity of Ha22-2(2,4)6.1 to 191P4D12.

Table VIII shows aa 1-180 protein sequence alignment of 191P4D12orthologs containing the V-domain. Only two amino acids in the ratortholog sequence, Thr-75 and Ser-90, are substituted in the murineortholog sequence for Ile and Asn respectively (marked in bold text). Itshould be noted that the corresponding amino acids in the human sequenceare Ala-76 and Ser-91. To determine if these amino acids comprise thebinding epitope of Ha22-2(2,4)6.1, several mutant constructs of 191P4D12and its murine ortholog were generated and expressed in PC3 cells (TableIX). “Murine” amino acids were introduced instead of a standard alaninesubstitution mutagenesis into human sequence and vice versa in the mousesequence.

It was shown that mutation of Ser-91 to Asn in the 191P4D12 severelyimpairs the binding of Ha22-2(2,4)6.1 confirming that this amino acid,Ser-91, is essential for binding and must comprise the epitoperecognized by the Ha22-2(2,4)6.1 MAb. Additional mutation of Ala inposition 76 (A76I, S91N double mutant) was also introduced into191P4D12. It was shown that binding of Ha22-2(2,4)6.1 to the doublemutant A76I, S91N is very similar to murine ortholog binding (FIG. 24).Conversely, mutation of Asn-90 in the murine sequence to Serdramatically improves binding of Ha22-2(2,4)6.1 to the murine mutantortholog further confirming the importance of the amino acid in thisposition for binding of Ha22-2(2,4)6.1. Binding of Ha22-2(2,4)6.1 to themurine ortholog double mutant A90S, I75A appears very similar to humanortholog of 191P4D12.

Taken together, these data prove that Ser-91 and Ala-76 play a crucialrole in binding of Ha22-2(2,4)6.1 to 191P4D12 protein on cell surfaceand constitute part of the epitope recognized by Ha22-2(2,4)6.1 on thesurface of 191P4D12.

To visualize this concept, we generated a computer model of the V-domainof 191P4D12 based on published crystal structure data for family membersof 191P4D12 and Ig-domain containing proteins using PyMOL (FIG. 25). Thepositions of Ala-76 (stippled) and Ser-91 (crosshatched) are shown.

Additionally, to further refine the binding site of Ha22-2(2,4)6.1 on191P4D12 molecule, we designed and expressed a fragment of 191P4D12corresponding to the V-domain on the surface of Rat(1)E cells. Thefollowing construct was generated in retroviral vector:

-   -   191P4D12 (aa1-150,347-510)

Binding of Ha22-2(2,4)6.1 MAb was assessed by FACS. As shown in FIG. 26,Ha22-2(2,4)6.1 binds to V-domain expressing cells (A) as well aswild-type 191P4D12 (B), but not to C1C2 domain expressing cellsgenerated earlier (C). This proves the binding site for this antibody islocated in the V-domain of 191P4D12 within first 150 amino acids.

The results show that the Ha22-2(2,4)6.1 MAb binds to the v-domain ofthe 191P4D12 protein from position aa 1-150 and additionally shows thatthe specific epitope comprising aa Ser-91 and aa Ala-76 are critical forbinding the Ha22-2(2,4)6.1 MAb.

Throughout this application, various website data content, publications,patent applications and patents are referenced. (Websites are referencedby their Uniform Resource Locator, or URL, addresses on the World WideWeb.) The disclosures of each of these references are herebyincorporated by reference herein in their entireties.

The present invention is not to be limited in scope by the embodimentsdisclosed herein, which are intended as single illustrations ofindividual aspects of the invention, and any that are functionallyequivalent are within the scope of the invention. Various modificationsto the models and methods of the invention, in addition to thosedescribed herein, will become apparent to those skilled in the art fromthe foregoing description and teachings, and are similarly intended tofall within the scope of the invention. Such modifications or otherembodiments can be practiced without departing from the true scope andspirit of the invention.

Tables

TABLE I Tissues that express 191P4D12 when malignant. Colon PancreasOvarian Breast Lung Bladder

TABLE II Amino Acid Abbreviations SINGLE LETTER THREE LETTER FULL NAME FPhe phenylalanine L Leu leucine S Ser serine Y Tyr tyrosine C Cyscysteine W Trp tryptophan P Pro proline H His histidine Q Gln glutamineR Arg arginine I Ile isoleucine M Met methionine T Thr threonine N Asnasparagine K Lys lysine V Val valine A Ala alanine D Asp aspartic acid EGlu glutamic acid G Gly glycine

TABLE III Amino Acid Substitution Matrix Adapted from the GCG Software9.0 BLOSUM62 amino acid substitution matrix (block substitution matrix).The higher the value, the more likely a substitution is found inrelated, natural proteins. A C D E F G H I K L M N P Q R S T V W Y . 4 0−2 −1 −2 0 −2 −1 −1 −1 −1 −2 −1 −1 −1 1 0 0 −3 −2 A 9 −3 −4 −2 −3 −3 −1−3 −1 −1 −3 −3 −3 −3 −1 −1 −1 −2 −2 C 6 2 −3 −1 −1 −3 −1 −4 −3 1 −1 0 −20 −1 −3 −4 −3 D 5 −3 −2 0 −3 1 −3 −2 0 −1 2 0 0 −1 −2 −3 −2 E 6 −3 −1 0−3 0 0 −3 −4 −3 −3 −2 −2 −1 1 3 F 6 −2 −4 −2 −4 −3 0 −2 −2 −2 0 −2 −3 −2−3 G 8 −3 −1 −3 −2 1 −2 0 0 −1 −2 −3 −2 2 H 4 −3 2 1 −3 −3 −3 −3 −2 −1 3−3 −1 I 5 −2 −1 0 −1 1 2 0 −1 −2 −3 −2 K 4 2 −3 −3 −2 −2 −2 −1 1 −2 −1 L5 −2 −2 0 −1 −1 −1 1 −1 −1 M 6 −2 0 0 1 0 −3 −4 −2 N 7 −1 −2 −1 −1 −2 −4−3 P 5 1 0 −1 −2 −2 −1 Q 5 −1 −1 −3 −3 −2 R 4 1 −2 −3 −2 S 5 0 −2 −2 T 4−3 −1 V 11 2 W 7 Y

TABLE IV General Method for Synthesis of vcMMAE Where: AA1 = Amino Acid1 AA2 = Amino Acid 2 AA5 = Amino Acid 5 DIL = Dolaisoleuine DAP =Dolaproine Linker = Val-Cit (vc)

TABLE V Biacore association and dissociation rates and resultingaffinity calculation kon, M-1s-1 koff, s-1 KD, M Ha22-2(2,4)6.1 3.8E+055.8E−03 1.6E−08 Ha22-2(2,4)6.1vcMMAE 4.5E+05 5.2E−03 1.1E−08

TABLE VI 191P4D12 constructs used in domain mapping assay ConstructsName 191P4D12 (aa 1-242, 347-510) VC1, Rat1(E) expressing line 191P4D12(aa 1-31, 147-510) C1C2, Rat1(E) expressing line 191P4D12 (aa 1-242)mFc-VC1, fusion protein 191P4D12 (aa 1-31, 147-346) mFc-C1C2, fusionprotein 191P4D12 (aa 1-141) mFc-V, fusion protein

TABLE VII Cyno Rat Murine PC3-191P4D12 ortholog ortholog ortholog Bmax(MFI) 816 1146 679 325 EC₅₀ (nM) 0.28 0.30 0.44 70.3

TABLE VIII (SEQ ID NOS: 11-13, in order of appearance) mouseMPLSLGAEMWGPEAWLR-LLFLASFTGQYSAGELETSDVVTVVLGQDAKLPCFYRGDPDE  59 ratMPLSLGAEMWGPEAWLL-LLFLASFTGRYSAGELETSDLVTVVLGQDAKLPCFYRGDPDE  59 humanMPLSLGAEMWGPEAWLLLLLLLASFTGRCPAGELETSDVVTVVLGQDAKLPCFYRGDSGE  60****************  **:******: .********:******************..* mouseQVGQVAWARVDPNEGIRELALLHSKYGLHVNPAYEDRVEQPPPPRDPLDGSVLLRNAVQA 119 ratQVGQVAWARVDPNEGTRELALLHSKYGLHVSPAYEDRVEQPPPPRDPLDGSILLRNAVQA 119 humanQVGQVAWARVDAGEGAQELALLHSKYGLHVSPAYEGRVEQPPPPRNPLDGSVLLRNAVQA 120***********..** :*************.****.*********:*****:******** mouseDEGEYECRVSTFPAGSFQARMRLRVLVPPLPSLNPGPPLEEGQGLTLAASCTAEGSPAPS 179 ratDEGEYECRVSTFPAGSFQARMRLRVLVPPLPSLNPGPPLEEGQGLTLAASCTAEGSPAPS 179 humanDEGEYECRVSTFPAGSFQARLRLRVLVPPLPSLNPGPALEEGQGLTLAASCTAEGSPAPS 180********************:****************.**********************

TABLE IX Mutant Double-mutant Wild type constructs constructs constructs191P4D12, wild type S91N S91N, A76I Murine ortholog of N90S N90S, I75A191P4D12, wild type

The invention claimed is:
 1. An anti-191P4D12 antibody or antigenbinding fragment thereof wherein the antibody or antigen bindingfragment thereof comprises a heavy chain variable region comprisingcomplementarity determining regions (CDRs) having the amino acidsequences of the heavy chain variable region CDRs set forth in SEQ IDNO:7 and a light chain variable region comprising CDRs having the aminoacid sequences of the light chain variable region CDRs set forth in SEQID NO:8.
 2. The antigen binding fragment of claim 1, wherein thefragment is an Fab, F(ab′)2, Fv or scFv fragment.
 3. The antibody ofclaim 1, wherein the antibody is a fully human antibody.
 4. The antibodyof claim 1, wherein the antibody is recombinantly produced.
 5. Anantibody drug conjugate comprising the antibody or antigen bindingfragment of claim 1 conjugated to a cytotoxic agent or cytostatic agent.6. The antibody drug conjugate of claim 5 wherein the cytotoxic agent ismonomethyl auristatin E.
 7. A pharmaceutical composition comprising theantibody drug conjugate of claim
 5. 8. The pharmaceutical composition ofclaim 7 wherein the cytotoxic agent is monomethyl auristatin E.